Net income attributable to noncontrolling interest

105

115

^[1]

Net income attributable to Ashland

$ 73

$ 92

$ 69

$ 91

Basic earnings per share - Note L

Income (loss) from continuing operations

$ 1.06

$ 0.46

$ 0.94

$ (0.59)

Income from discontinued operations attributable to Ashland

0.11

1.02

0.16

2.06

Net income attributable to Ashland

1.17

1.48

1.10

1.47

Diluted earnings per share - Note L

Income (loss) from continuing operations

1.04

0.46

0.93

(0.59)

Income from discontinued operations attributable to Ashland

0.11

1.01

0.15

2.06

Net income attributable to Ashland

$ 1.15

$ 1.47

$ 1.08

$ 1.47

COMPREHENSIVE INCOME (LOSS)

Other comprehensive income (loss), net of tax

$ 73

$ 105

$ 69

$ 115

Unrealized translation gain (loss)

(86)

Pension and postretirement obligation adjustment

(2)

(4)

Net change in available-for-sale securities

(6)

Other comprehensive income (loss)

(84)

Comprehensive income

122

169

129

Comprehensive income attributable to noncontrolling interest

Comprehensive income attributable to Ashland

$ 122

$ 155

$ 129

$ 7

[1]	For the three and six months ended March 31, 2017, this represents the income attributable to the previous noncontrolling interest in Valvoline Inc., whose results are now included within discontinued operations. See Note B for more information.

CONDENSED CONSOLIDATED BALANCE SHEETS (unaudited) - USD ($)
$ in Millions

Mar. 31, 2018

Sep. 30, 2017

Current assets

Net property, plant and equipment

$ 225

$ 566

Accounts receivable

^[1]

717

612

Inventories - Note F

649

634

Other assets

122

Total current assets

1,713

1,903

Property, plant and equipment

Cost

3,859

3,762

Accumulated depreciation

1,919

1,792

1,940

1,970

Goodwill - Note G

2,503

2,465

Intangibles - Note G

1,290

1,319

Restricted investments - Note E

303

302

Asbestos insurance receivable - Note K

203

209

Deferred and other income taxes

Other assets

461

422

Total noncurrent assets

6,728

6,715

Total assets

8,441

8,618

Current liabilities

Short-term debt - Note H

235

Trade and other payables

387

409

Accrued expenses and other liabilities

266

324

Total current liabilities

712

968

Noncurrent liabilities

Long-term debt - Note H

2,579

2,584

Asbestos litigation reserve - Note K

665

694

Deferred and other income taxes

243

375

Employee benefit obligations - Note J

190

191

Other liabilities

541

400

Total noncurrent liabilities

4,218

4,244

Commitments and contingencies - Note K

Stockholders’ equity

3,511

3,406

Total liabilities and stockholders' equity

$ 8,441

$ 8,618

[1]	Accounts receivable includes an allowance for doubtful accounts of $9 million at both March 31, 2018 and September 30, 2017.

STATEMENT OF CONSOLIDATED EQUITY (unaudited) - 6 months ended Mar. 31, 2018 - USD ($)
$ in Millions

Total

Common stock [Member]

Paid-in capital [Member]

Retained earnings [Member]

Accumulated other comprehensive income (loss) [Member]

^[1]

Beginning Balance at Sep. 30, 2017

$ 3,406

$ 1

$ 931

$ 2,696

$ (222)

Total comprehensive income (loss)

Other comprehensive income (loss)

Regular dividends, $0.45 per common share

(28)

Common shares issued under stock incentive and other plans

^[2]

Ending Balance at Mar. 31, 2018

$ 3,511

$ 1

$ 935

$ 2,737

$ (162)

[1]

At March 31, 2018 and September 30, 2017, the after-tax accumulated other comprehensive loss attributable to Ashland of $162 million and $222 million, respectively, was each comprised of net unrealized translation losses of $188 million and $246 million, respectively, net unrealized gains on available-for-sale securities of $23 million and $21 million, respectively, and unrecognized prior service credits as a result of certain employee benefit plan amendments of $3 million for each period.

[2]

Common shares issued were 265,821 for the six months ended March 31, 2018.

STATEMENT OF CONSOLIDATED EQUITY (unaudited) (Parenthetical) - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2018	Sep. 30, 2017
Statement Of Stockholders Equity [Abstract]
Dividends on common stock	$ 0.45
Accumulated other comprehensive loss	$ (162)	$ (222)
Unrecognized prior service credits	3	3
Net unrealized translation loss	(188)	(246)
Available-for-sale securities unrealized gain	$ 23	$ 21
Common shares issued (in shares)	265,821

STATEMENTS OF CONDENSED CONSOLIDATED CASH FLOWS (unaudited) - USD ($)
$ in Millions

6 Months Ended

Mar. 31, 2018

Mar. 31, 2017

CASH FLOWS PROVIDED (USED) BY OPERATING ACTIVITIES FROM CONTINUING OPERATIONS

Income from discontinued operations (net of income taxes)

$ 69

$ 115

(10)

(152)

Adjustments to reconcile income from continuing operations to cash flows from operating activities

Depreciation and amortization

161

134

Original issue discount and debt issuance costs amortization

Deferred income taxes

Stock based compensation expense

Excess tax benefit on stock based compensation

Gain on early retirement of debt

(3)

Realized gains and investment income on available-for-sale securities

(8)

(7)

Net loss on divestitures

Pension contributions

(7)

(4)

Gain on post-employment plan remeasurement

(2)

Change in operating assets and liabilities

^[1]

(229)

(192)

Total cash flows used by operating activities from continuing operations

(2)

CASH FLOWS PROVIDED (USED) BY INVESTING ACTIVITIES FROM CONTINUING OPERATIONS

Additions to property, plant and equipment

(60)

(73)

Proceeds from disposal of property, plant and equipment

Purchase of operations - net of cash acquired

(11)

Proceeds (uses) from sale of operations

(1)

Life insurance payments

(37)

Net purchase of funds restricted for specific transactions

(8)

(2)

Reimbursement from restricted investments

Proceeds from sales of available-for-sale securities

Purchase of available-for-sale securities

(17)

(19)

Proceeds from the settlement of derivative instruments

Payments for the settlement of derivative instruments

(3)

Total cash flows used by investing activities from continuing operations

(100)

(63)

CASH FLOWS PROVIDED (USED) BY FINANCING ACTIVITIES FROM CONTINUING OPERATIONS

Repayment of long-term debt

(3)

(254)

Premium on long-term debt

(5)

Repayment of short-term debt

(181)

(151)

Debt issuance costs

(2)

Cash dividends paid

(28)

(48)

Stock based compensation employee withholding taxes paid in cash

(8)

(13)

Total cash flows used by financing activities from continuing operations

(220)

(473)

CASH PROVIDED (USED) BY CONTINUING OPERATIONS

(320)

(538)

Cash provided (used) by discontinued operations

Operating cash flows

(24)

Investing cash flows

(79)

Financing cash flows

(17)

Total cash used by discontinued operations

(24)

(36)

Effect of currency exchange rate changes on cash and cash equivalents

(10)

DECREASE IN CASH AND CASH EQUIVALENTS

(341)

(584)

CASH AND CASH EQUIVALENTS - BEGINNING OF PERIOD

566

1,017

Change in cash and cash equivalents held by Valvoline

CASH AND CASH EQUIVALENTS - END OF PERIOD

$ 225

$ 470

[1]	Excludes changes resulting from operations acquired or sold.

Significant Accounting Policies	6 Months Ended
Significant Accounting Policies	Mar. 31, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Significant Accounting Policies	NOTE A – SIGNIFICANT ACCOUNTING POLICIES Basis of presentation The accompanying unaudited Condensed Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States for interim financial reporting and Securities and Exchange Commission (SEC) regulations. In the opinion of management, all adjustments considered necessary for a fair presentation have been included. Additionally, certain prior period data, primarily related to discontinued operations, have been reclassified in the Consolidated Financial Statements and accompanying notes to conform to the current period presentation, as further described in this section. These statements omit certain information and footnote disclosures required for complete annual financial statements and, therefore, should be read in conjunction with Ashland’s Annual Report on Form 10-K for the fiscal year ended September 30, 2017. Results of operations for the period ended March 31, 2018 are not necessarily indicative of the expected results for the remaining quarters in the fiscal year. On May 12, 2017, Ashland completed the distribution of its remaining 170 million shares of common stock of Valvoline Inc. which represented approximately 83% of the total outstanding shares of Valvoline Inc.'s common stock. This separation from Valvoline represented a strategic shift in Ashland's business and qualified as a discontinued operation. Accordingly, Valvoline's operating results and cash flows for the three and six months ended March 31, 2017 have been classified as discontinued operations within the Condensed Consolidated Financial Statements. See Note B for additional information on the separation of Valvoline Inc. Subsequent to completing the separation from Valvoline Inc., Ashland's operations are managed within the following three reportable segments: Specialty Ingredients, Composites and Intermediates and Solvents. Use of estimates, risks and uncertainties The preparation of Ashland’s Condensed Consolidated Financial Statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and the disclosures of contingent assets and liabilities. Significant items that are subject to such estimates and assumptions include, but are not limited to, long-lived assets (including goodwill and other intangible assets), income taxes and liabilities and receivables associated with asbestos litigation and environmental remediation. Although management bases its estimates on historical experience and various other assumptions that are believed to be reasonable under the circumstances, actual results could differ significantly from the estimates under different assumptions or conditions. Ashland’s results are affected by domestic and international economic, political, legislative, regulatory and legal actions. Economic conditions, such as recessionary trends, inflation, interest and monetary exchange rates, government fiscal policies and changes in the prices of certain key raw materials, can have a significant effect on operations. While Ashland maintains reserves for anticipated liabilities and carries various levels of insurance, Ashland could be affected by civil, criminal, regulatory or administrative actions, claims or proceedings relating to asbestos, environmental remediation or other matters. New accounting standards A description of new U.S. GAAP accounting standards issued or adopted during the current year is required in interim financial reporting. A detailed listing of new accounting standards relevant to Ashland is included in the Annual Report on Form 10-K for the fiscal year ended September 30, 2017. The following standards relevant to Ashland were either issued or adopted in the current period, or will become effective in a subsequent period. In May 2014, the FASB issued accounting guidance outlining a single comprehensive five step model for entities to use in accounting for revenue arising from contracts with customers (ASC 606 Revenue from Contracts with Customers). The new guidance supersedes most current revenue recognition guidance, in an effort to converge the revenue recognition principles within U.S. GAAP. This new guidance also requires entities to disclose certain quantitative and qualitative information regarding the nature, amount, timing and uncertainty of qualifying revenue and cash flows arising from contracts with customers. Entities have the option of using a full retrospective or a modified retrospective approach to adopt the new guidance. Ashland has identified an implementation team that is currently evaluating the impact of the new standard on the Condensed Consolidated Financial Statements and the adoption method options available as well as the overall impact the new guidance will have on the organization. The assessment process consists of categorizing Ashland’s revenue streams and reviewing the current internal accounting policies and practices to determine potential differences that would result from applying the requirements of the new standard to revenue contracts. Additional discussions and meetings with each revenue stream team have occurred to solicit input, identify potential impacts and appropriate changes to Ashland’s business processes, systems and controls to support the revenue recognition and disclosure requirements under the new standard. Based on various preliminary assessments conducted to date, Ashland has identified agreements with distributors and customers that are subject to rebate and incentive programs that could contain elements of material rights and/or variable consideration. Ashland does not currently believe that these elements would result in a material change to how revenue would be recognized for these agreements. Ashland currently intends to adopt this standard using the modified retrospective approach and does not believe the impact will be material to the Condensed Consolidated Financial Statements but does expect there to be significant additional disclosures within the Notes to Condensed Consolidated Financial Statements. This guidance becomes effective for Ashland on October 1, 2018. In February 2018, the FASB issued guidance which permits entities to reclassify tax effects stranded in accumulated other comprehensive income (AOCI) as a result of U.S. tax reform legislation to retained earnings. Additionally, this guidance requires entities to disclose whether they made an election to reclassify the tax effects and to disclose their accounting policy for releasing income tax effects from AOCI. This guidance becomes effective for Ashland on October 1, 2019. Ashland is currently evaluating the impact this guidance may have on Ashland’s Condensed Consolidated Financial Statements. In March 2017, the FASB issued accounting guidance that will change how employers who sponsor defined benefit pension and/or postretirement benefit plans present the net periodic benefit cost in the Statement of Consolidated Comprehensive Income (Loss). This guidance requires employers to present the service cost component of net periodic benefit cost in the same caption within the Statement of Consolidated Comprehensive Income (Loss) as other employee compensation costs from services rendered during the period. All other components of the net periodic benefit cost will be presented separately outside of the operating income caption. This guidance must be applied retrospectively. Ashland elected to early adopt this guidance on October 1, 2017, which resulted in a reclassification of $3 million in income from the selling, general and administrative expense and cost of sales captions to the other net periodic benefit income caption in the Statement of Consolidated Comprehensive Income (Loss) for the six months ended March 31, 2017. The components of net periodic benefits income (costs) reclassified primarily relate to interest cost, expected return on assets, curtailments, settlements and actuarial gains and losses. Ashland did not have to adjust the classification of service cost since it previously was recorded within the caption required by the new guidance. See Note J for additional information on net periodic benefit costs. In March 2016, the FASB issued new accounting guidance for certain aspects of share-based payments to employees. This guidance requires all excess tax benefits and tax deficiencies related to share-based payments to be recognized as income tax expense in the Statements of Consolidated Comprehensive Income (Loss) instead of additional paid-in capital, and changes the classification of excess tax benefits from a financing activity to an operating activity within the Statements of Condensed Consolidated Cash Flows. This guidance also allows entities to make an accounting policy election to either estimate the number of awards that are expected to vest or account for forfeitures when they occur. In addition, this guidance increases the amount an employer can withhold to cover income taxes on awards and still qualify for equity classification and requires that cash paid by an employer when directly withholding shares for tax-withholding purposes be classified as a financing activity within the Statements of Condensed Consolidated Cash Flows. The guidance became effective for Ashland and was adopted on October 1, 2017. The guidance specifically related to the Statements of Consolidated Comprehensive Income (Loss) was adopted prospectively while the guidance related to the Statements of Condensed Consolidated Cash Flows was adopted retrospectively, as required by the guidance. Additionally, Ashland made a policy election to account for forfeitures when they occur across all share-based awards. Upon adoption, the overall impact on Ashland's Condensed Consolidated Financial Statements was not significant.

Valvoline

6 Months Ended

Mar. 31, 2018

Valvoline

NOTE B – VALVOLINE

Ashland Separation of Valvoline

On September 22, 2015, Ashland announced that the Board of Directors approved proceeding with a plan to separate Ashland into two independent, publicly traded companies comprising of the new Ashland (now known as Ashland Global Holdings Inc.) and Valvoline Inc. The initial step of the separation, the initial public offering (IPO) of Valvoline Inc., closed on September 28, 2016. As discussed further within the Final Separation section of this Note, Ashland completed the distribution of its remaining shares in Valvoline Inc. on May 12, 2017. The new Ashland is a premier global leader in providing specialty chemical solutions to customers in a wide range of consumer and industrial markets. Key markets and applications include pharmaceutical, personal care, food and beverage, architectural coatings, adhesives, automotive, construction and energy.

After completing the IPO on September 28, 2016 and before the distribution of its remaining shares on May 12, 2017, Ashland owned 170 million shares of Valvoline Inc.’s common stock which represented approximately 83% of the total outstanding shares of Valvoline Inc.’s common stock. As a result, Ashland continued to consolidate Valvoline within the Condensed Consolidated Financial Statements up until the distribution of the remaining shares. The resulting outside stockholders’ interests in Valvoline Inc., which was approximately 17%, was presented separately as a noncontrolling interest within Ashland’s equity in the Condensed Consolidated Balance Sheets up until the distribution of the remaining shares. The amount of consolidated net income attributable to these minority holders is presented as a separate caption on the Statements of Consolidated Comprehensive Income (Loss) for the three and six months ended March 31, 2017.

Final Separation

Ashland completed the distribution of its remaining 170 million shares of common stock of Valvoline Inc. as a pro rata dividend on shares of Ashland common stock outstanding at the close of business on the record date of May 5, 2017. Based on the shares of Ashland common stock outstanding as of May 5, 2017, the record date for the distribution, each share of Ashland common stock received 2.745338 shares of Valvoline common stock in the distribution. The distribution was recorded at the carrying amount of Valvoline Inc.'s net assets which was a deficit of $187 million as of May 12, 2017, as follows:

	May 12
(In millions)	2017
ASSETS
Current assets
Cash and cash equivalents	$	179
Accounts receivable, net		385
Inventories		153
Other current assets		24
Total current assets		741
Noncurrent assets
Net property, plant and equipment		357
Goodwill		329
Equity and other unconsolidated investments		31
Deferred income taxes		391
Other noncurrent assets		93
Total noncurrent assets		1,201
Total assets		1,942
LIABILITIES AND EQUITY
Current liabilities
Short-term debt		75
Current portion of long-term debt		16
Trade and other payables		353
Other current liabilities		34
Total current liabilities		478
Noncurrent liabilities
Long-term debt		662
Employee benefit obligations		826
Other long-term liabilities		163
Total noncurrent liabilities		1,651
Total liabilities		2,129
Net deficit	$	(187	)

A Tax Matters Agreement between Ashland and Valvoline Inc. governs the rights and obligations after the separation regarding certain income taxes and other taxes, including certain tax liabilities and benefits, attributes, returns and contests.

Discontinued Operations Assessment

Valvoline met the criteria to qualify as a discontinued operation and accordingly, its operating results and cash flows for the three and six months ended March 31, 2017 have been classified as discontinued operations within the Condensed Consolidated Financial Statements. See Note D for more information.

Costs of transaction

Ashland recognized separation costs of $2 million and $26 million for the three months ended March 31, 2018 and 2017, respectively, and $8 million and $54 million for the six months ended March 31, 2018 and 2017, respectively. Of these amounts, $7 million and $12 million of separation costs directly related to Valvoline and were included within the discontinued operations caption of the Statement of Consolidated Comprehensive Income (Loss) for the three and six months ended March 31, 2017, respectively. Otherwise, separation costs are recorded within the selling, general and administrative expense caption of the Statements of Consolidated Comprehensive Income (Loss).

Acquisitions

6 Months Ended

Mar. 31, 2018

Business Combinations [Abstract]

Discontinued Operations And Disposal Groups [Abstract]

NOTE C – ACQUISITIONS

Pharmachem

Background

On May 17, 2017, Ashland completed its acquisition of the stock of Pharmachem Laboratories, Inc. (Pharmachem), a leading provider of quality ingredients to the global health and wellness industries and high-value differentiated products to fragrance and flavor houses. With annual revenues of approximately $300 million and 14 manufacturing facilities in the United States and Mexico, New Jersey-based Pharmachem develops, manufactures and supplies custom and branded nutritional and fragrance products. Ashland has included Pharmachem within the Specialty Ingredients reportable segment.

Purchase price allocation

The acquisition was recorded by Ashland using the purchase method of accounting in accordance with applicable U.S. GAAP whereby the total purchase price was allocated to tangible and intangible assets and liabilities acquired based on respective fair values.

The all-cash purchase price of Pharmachem was $680 million which included working capital adjustments of approximately $20 million. The following table summarizes the current preliminary values of the assets acquired and liabilities assumed at the date of acquisition.

	At
	May 17, 2017
Preliminary purchase price allocation (in millions)	As Adjusted
Assets:
Accounts receivable	$	52
Inventory		74
Other current assets		4
Intangible assets		330
Goodwill		288
Property, plant and equipment		97
Other noncurrent assets		20
Liabilities:
Accounts payable		(33	)
Deferred tax - net		(138	)
Other noncurrent liabilities		(14	)
Total purchase price	$	680

As of March 31, 2018, the purchase price allocation for the acquisition was preliminary. Adjustments to the current fair value estimates in the above table may occur as the process conducted for various valuations and assessments, including certain tangible and intangible assets, are finalized. Goodwill was calculated as the excess of the consideration transferred over the net assets recognized and represents the estimated future economic benefits arising from other assets acquired that could not be individually identified and separately recognized. The factors contributing to the recognition of goodwill were based on strategic benefits that are expected to be realized from the acquisition. None of the goodwill is expected to be deductible for income tax purposes. During the current quarter, adjustments of $1 million were made to goodwill and accounts payable.

Intangible assets identified

The purchase price allocation included $330 million of certain definite-lived intangible assets which are being amortized over the estimated useful life in proportion to the economic benefits consumed. The determination of the useful lives is based upon various industry studies, historical acquisition experience, economic factors, and future cash flows of the combined company. In addition, Ashland reviewed certain technological trends and considered the relative stability in the current Pharmachem customer base.

The following details the total intangible assets identified as of May 17, 2017.

Vornia Limited

In January 2018, Ashland completed the acquisition of Vornia Limited for $12 million, of which $1 million will be paid in future periods. Vornia Limited’s principal activity is the design, development and fabrication of customized biomaterial solutions. The purchase price allocation primarily included $8 million of intellectual property and $4 million of goodwill and has been included within the Specialty Ingredients reportable segment.

Discontinued Operations

6 Months Ended

Mar. 31, 2018

Discontinued Operations

NOTE D – DISCONTINUED OPERATIONS

In previous periods, Ashland has divested certain businesses that have qualified as discontinued operations. The operating results from these divested businesses and subsequent adjustments related to ongoing assessments of certain retained liabilities and tax items have been recorded within the discontinued operations caption in the Statements of Consolidated Comprehensive Income (Loss) for all periods presented and are discussed further within this note.

As previously discussed in Notes A and B, Ashland completed the distribution of its remaining 170 million shares of common stock of Valvoline Inc. on May 12, 2017. Ashland determined that the Valvoline separation qualified as a discontinued operation, in accordance with U.S. GAAP, since it represents a strategic shift for Ashland and has a major effect on Ashland's operations and financial results. Accordingly, Valvoline's operating results and cash flows for the three and six months ended March 31, 2017 have been classified as discontinued operations within the Condensed Consolidated Financial Statements. The activity during the three and six months ended March 31, 2018 generally represents subsequent adjustments that were made in conjunction with the Tax Matters Agreement.

Ashland is subject to liabilities from claims alleging personal injury caused by exposure to asbestos. Such claims result primarily from indemnification obligations undertaken in 1990 in connection with the sale of Riley Stoker Corporation (Riley), a former subsidiary of Ashland, which qualified as a discontinued operation, and from the 2009 acquisition of Hercules LLC (formerly Hercules Incorporated), a wholly-owned subsidiary of Ashland. During the three and six months ended March 31, 2018, Ashland recorded $3 million of income within the discontinued operations caption related to receipts from insurance carriers for asbestos-related litigation.

On July 31, 2014, Ashland completed the sale of the Ashland Water Technologies (Water Technologies) business to Clayton, Dubilier & Rice. Ashland made subsequent post-closing adjustments to the discontinued operations caption as defined by the definitive agreement during the three and six months ended March 31, 2017.

Components of amounts reflected in the Statements of Consolidated Comprehensive Income (Loss) related to discontinued operations are presented in the following table for the three and six months ended March 31, 2018 and 2017.

	Three months ended				Six months ended
	March 31				March 31
(In millions)	2018		2017		2018		2017
Income from discontinued operations (net of tax)
Valvoline	$	4	$	73	$	7	$	149
Asbestos-related litigation		3		—		3		—
Water Technologies		—		3		—		3
Total income from discontinued operations (net of tax)	$	7	$	76	$	10	$	152

The following table presents a reconciliation of the historically reported captions within Ashland's Statements of Consolidated Income (Loss) for the income from discontinued operations attributable to Valvoline for the three and six months ended March 31, 2017.

	Three			Six
	months ended			months ended
(In millions)	March 31, 2017			March 31, 2017
Income (loss) from discontinued operations attributable to Valvoline
Sales	$	514		$	1,003
Cost of sales		(310	)		(603	)
Selling, general and administrative expense		(90	)		(172	)
Research and development expense		(3	)		(6	)
Equity and other income		6			15
Pretax operating income of discontinued operations		117			237
Net interest and other financing expense		(9	)		(18	)
Pretax income of discontinued operations		108			219
Income tax expense		(35	)		(70	)
Income from discontinued operations	$	73		$	149

Fair Value Measurements

6 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

Fair Value Measurements

NOTE E – FAIR VALUE MEASUREMENTS

As required by U.S. GAAP, Ashland uses applicable guidance for defining fair value, the initial recording and periodic remeasurement of certain assets and liabilities measured at fair value and related disclosures for instruments measured at fair value. Fair value accounting guidance establishes a fair value hierarchy, which prioritizes the inputs to valuation techniques used to measure fair value into three broad levels. The fair value hierarchy gives the highest priority to quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). An instrument’s categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the instrument’s fair value measurement. The three levels within the fair value hierarchy are described as follows.

Level 1 – Observable inputs such as unadjusted quoted prices in active markets for identical assets or liabilities.

Level 2 – Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. These include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active.

Level 3 – Unobservable inputs for the asset or liability for which there is little, if any, market activity at the measurement date. Unobservable inputs reflect Ashland’s own assumptions about what market participants would use to price the asset or liability. The inputs are developed based on the best information available in the circumstances, which might include Ashland’s own financial data such as internally developed pricing models, discounted cash flow methodologies, as well as instruments for which the fair value determination requires significant management judgment.

For assets that are measured using quoted prices in active markets (Level 1), the total fair value is the published market price per unit multiplied by the number of units held without consideration of transaction costs. Assets and liabilities that are measured using significant other observable inputs (Level 2) are primarily valued by reference to quoted prices of similar assets or liabilities in active markets, adjusted for any terms specific to that asset or liability. For all other assets and liabilities for which unobservable inputs are used (Level 3), fair value is derived using fair value models, such as a discounted cash flow model or other standard pricing models that Ashland deems reasonable.

The following table summarizes financial instruments subject to recurring fair value measurements as of March 31, 2018.

	Carrying		Total fair		Quoted prices in active markets for identical assets		Significant other observable inputs		Significant unobservable inputs
(In millions)	value		value		Level 1		Level 2		Level 3
Assets
Cash and cash equivalents	$	225	$	225	$	225	$	—	$	—
Restricted investments (a)		333		333		333		—		—
Deferred compensation investments (b)		160		160		—		160		—
Investment of captive insurance company		4		4		4		—		—
Foreign currency derivatives		4		4		—		4		—
Total assets at fair value	$	726	$	726	$	562	$	164	$	—
Liabilities
Foreign currency derivatives	$	21	$	21	$	—	$	21	$	—

(a)

Included in restricted investments is $30 million classified in the other current assets caption on the Condensed Consolidated Balance Sheets.

(b)

Included in other noncurrent assets in the Condensed Consolidated Balance Sheets.

The following table summarizes financial asset instruments subject to recurring fair value measurements as of September 30, 2017.

	Carrying		Total fair		Quoted prices in active markets for identical assets		Significant other observable inputs		Significant unobservable inputs
(In millions)	value		value		Level 1		Level 2		Level 3
Assets
Cash and cash equivalents	$	566	$	566	$	566	$	—	$	—
Restricted investments (a)		332		332		332		—		—
Deferred compensation investments (b)		158		158		—		158		—
Investment of captive insurance company		3		3		3		—		—
Foreign currency derivatives		2		2		—		2		—
Total assets at fair value	$	1,061	$	1,061	$	901	$	160	$	—
Liabilities
Foreign currency derivatives	$	36	$	36	$	—	$	36	$	—

(a)

Included in restricted investments is $30 million classified in the other current assets caption on the Condensed Consolidated Balance Sheets.

(b)

Included in other noncurrent assets in the Condensed Consolidated Balance Sheets.

Restricted investments

During 2015, Ashland and Hercules entered into a comprehensive settlement agreement related to certain insurance coverage for asbestos bodily injury claims with Underwriters at Lloyd’s, certain London Companies and Chartis (AIG) member companies, along with National Indemnity Company and Resolute Management, Inc., under which Ashland and Hercules received a total of $398 million (the January 2015 asbestos insurance settlement). Ashland placed $335 million of the settlement funds from the January 2015 asbestos insurance settlement into a renewable annual trust restricted for the purpose of paying ongoing and future litigation defense and claim settlement costs incurred in conjunction with asbestos claims. These funds were classified primarily as noncurrent restricted investment assets, with $30 million classified within other current assets, in the Condensed Consolidated Balance Sheets as of March 31, 2018 and September 30, 2017, respectively.

During 2015, Ashland diversified the restricted investments received from the January 2015 asbestos insurance settlement into primarily equity and corporate bond mutual funds that are designated as available-for-sale securities, classified as Level 1 measurements within the fair value hierarchy. Available-for-sale securities are reported at fair value with unrealized gains and losses, net of related deferred income taxes, included in the stockholders' equity section of the Condensed Consolidated Balance Sheets as a component of accumulated other comprehensive income (AOCI). Investment income and realized gains and losses on the available-for-sale securities are reported in the net interest and other financing expense caption in the Statements of Consolidated Comprehensive Income (Loss). The following table provides a summary of the available-for-sale securities portfolio as of March 31, 2018 and September 30, 2017:

(In millions)	March 31 2018			September 30 2017
Original cost	$	335		$	335
Accumulated adjustments, net		(38	)		(24	)
Adjusted cost, beginning of year (a)		297			311
Investment income (b)		4			9
Net unrealized gain		37			35
Realized gains		4			2
Settlement funds		8			2
Disbursements		(17	)		(27	)
Fair value	$	333		$	332

(a)

The accumulated adjustments include investment income, realized gains, disbursements and settlements recorded in previous periods.

(b)

Investment income for the demand deposit includes interest income as well as dividend income transferred from the equity and corporate bond mutual funds.

The following table presents gross unrealized gains and losses for the restricted investment available-for-sale securities as of March 31, 2018 and September 30, 2017:

			Gross		Gross
(In millions)	Adjusted Cost		Unrealized Gain		Unrealized Loss			Fair Value
As of March 31, 2018
Demand deposit	$	22	$	—	$	—		$	22
Equity mutual fund		154		40		—			194
Corporate bond mutual fund		120		—		(3	)		117
Fair value	$	296	$	40	$	(3	)	$	333

As of September 30, 2017
Demand deposit	$	9	$	—	$	—		$	9
Equity mutual fund		168		34		—			202
Corporate bond mutual fund		120		1		—			121
Fair value	$	297	$	35	$	—		$	332

The unrealized gains and losses as of March 31, 2018 and September 30, 2017 were recognized within AOCI. Ashland invests in highly-rated investment grade mutual funds. No other-than-temporary impairment was recognized in AOCI during the three and six months ended March 31, 2018 and 2017.

The following table presents the investment income, realized gains and disbursements related to the investments within the portfolio for the three and six months ended March 31, 2018 and 2017.

	Three months ended						Six months ended
	March 31						March 31
(In millions)	2018			2017			2018			2017
Investment income	$	2		$	2		$	4		$	5
Realized gains		3			2			4			2
Disbursements		(12	)		(12	)		(17	)		(12	)

Deferred compensation investments

Deferred compensation investments consist of Level 2 measurements within the fair value hierarchy which are comprised primarily of a guaranteed interest fund, a common stock index fund and an intermediate government bond fund. Gains and losses related to deferred compensation investments are immediately recognized within the Statements of Consolidated Comprehensive Income (Loss).

Foreign currency derivatives

Ashland conducts business in a variety of foreign currencies. Accordingly, Ashland regularly uses foreign currency derivative instruments to manage exposure on certain transactions denominated in foreign currencies to curtail potential earnings volatility effects on certain assets and liabilities, including short-term inter-company loans, denominated in currencies other than Ashland’s functional currency of an entity. These derivative contracts generally require exchange of one foreign currency for another at a fixed rate at a future date and generally have maturities of less than twelve months. All contracts are valued at fair value with net changes in fair value recorded within the selling, general and administrative expense caption. The impacts of these contracts were largely offset by gains and losses resulting from the impact of changes in exchange rates on transactions denominated in non-functional currencies. The following table summarizes the net gains and losses recognized during the three and six months ended March 31, 2018 and 2017 within the Statements of Consolidated Comprehensive Income (Loss).

	Three months ended					Six months ended
	March 31					March 31
(In millions)	2018			2017		2018			2017
Foreign currency derivative gains (losses)	$	(16	)	$	8	$	(27	)	$	—

The following table summarizes the fair values of the outstanding foreign currency derivatives as of March 31, 2018 and September 30, 2017 included in accounts receivable and accrued expenses and other liabilities of the Condensed Consolidated Balance Sheets.

	March 31		September 30
(In millions)	2018		2017
Foreign currency derivative assets	$	4	$	2
Notional contract values		302		79

Foreign currency derivative liabilities	$	21	$	36
Notional contract values		958		1,601

Other financial instruments

At March 31, 2018 and September 30, 2017, Ashland's long-term debt (including the current portion and excluding debt issuance cost discounts) had a carrying value of $2,613 million and $2,615 million, respectively, compared to a fair value of $2,710 million and $2,768 million, respectively. The fair values of long-term debt are based on quoted market prices or, if market prices are not available, the present values of the underlying cash flows discounted at Ashland’s incremental borrowing rates, which are deemed to be Level 2 measurements within the fair value hierarchy.

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

Goodwill And Intangible Assets Disclosure [Abstract]

Inventories

6 Months Ended

Mar. 31, 2018

Inventory Disclosure [Abstract]

Inventories

NOTE F – INVENTORIES

Inventories are carried at the lower of cost or net realizable value. Inventories are primarily stated at cost using the weighted-average cost method. In addition, certain inventories are valued at cost using the last-in, first-out (LIFO) method.

The following table summarizes Ashland’s inventories as of the reported Condensed Consolidated Balance Sheet dates.

(In millions)	March 31, 2018			September 30, 2017
Finished products	$	404		$	390
Raw materials, supplies and work in process		248			245
LIFO carrying values		(3	)		(1	)
	$	649		$	634

Goodwill and Other Intangibles

6 Months Ended

Mar. 31, 2018

Goodwill and Other Intangibles

NOTE G – GOODWILL AND OTHER INTANGIBLES

Goodwill

Ashland reviews goodwill and indefinite-lived intangible assets for impairment annually or when events and circumstances indicate an impairment may have occurred. This annual assessment is performed as of July 1 and consists of Ashland determining each reporting unit’s current fair value compared to its current carrying value. For its July 1, 2017 assessment, Ashland determined that its reporting units for the allocation of goodwill are its three reportable segments: Specialty Ingredients, Composites and Intermediates and Solvents. At that time, Ashland determined no additional impairment existed.

The following is a progression of goodwill by reportable segment for the six months ended March 31, 2018.

	Specialty				Intermediates
(In millions)	Ingredients		Composites		and Solvents		(a)	Total
Balance at September 30, 2017	$	2,315	$	150	$	—		$	2,465
Acquisitions (b)		4		—		—			4
Currency translation		33		1		—			34
Balance at March 31, 2018	$	2,352	$	151	$	—		$	2,503

(a)

As of March 31, 2018, there was accumulated impairment of $171 million related to the Intermediates and Solvents reportable segment.

(b)

Relates to the acquisition of Vornia Limited during the six months ended March 31, 2018. See Note C for more information.

Other intangible assets

Intangible assets principally consist of trademarks and trade names, intellectual property and customer and supplier relationships. Intangible assets classified as finite are amortized on a straight-line basis over their estimated useful lives. The cost of trademarks and trade names is amortized principally over 3 to 25 years, intellectual property over 5 to 25 years, and customer and supplier relationships over 3 to 24 years.

Ashland annually reviews indefinite-lived intangible assets for possible impairment or whenever events or changes in circumstances indicate that carrying amounts may not be recoverable.

Intangible assets were comprised of the following as of March 31, 2018 and September 30, 2017.

	March 31, 2018
	Gross					Net
	carrying		Accumulated			carrying
(In millions)	amount		amortization			amount
Definite-lived intangibles
Trademarks and trade names	$	67	$	(23	)	$	44
Intellectual property		773		(354	)		419
Customer and supplier relationships		786		(260	)		526

Total definite-lived intangibles		1,626		(637	)		989
Indefinite-lived intangibles
Trademarks and trade names		301		—			301
Total intangible assets	$	1,927	$	(637	)	$	1,290

	September 30, 2017
	Gross					Net
	carrying		Accumulated			carrying
(In millions)	amount		amortization			amount
Definite-lived intangibles
Trademarks and trade names	$	67	$	(22	)	$	45
Intellectual property		757		(326	)		431
Customer and supplier relationships		777		(235	)		542
Total definite-lived intangibles		1,601		(583	)		1,018

Indefinite-lived intangibles
Trademarks and trade names		301		—			301
Total intangible assets	$	1,902	$	(583	)	$	1,319

Amortization expense recognized on intangible assets was $24 million and $19 million for the three months ended March 31, 2018 and 2017, respectively, and $48 million and $38 million for the six months ended March 31, 2018 and 2017, respectively, and is included in the selling, general and administrative expense caption of the Statements of Consolidated Comprehensive Income (Loss). Estimated amortization expense for future periods is $95 million in 2018 (includes six months actual and six months estimated), $91 million in 2019, $90 million in 2020, $90 million in 2021 and $88 million in 2022. The amortization expense for future periods is an estimate. Actual amounts may change from such estimated amounts due to fluctuations in foreign currency exchange rates, additional intangible asset acquisitions and divestitures, potential impairment, accelerated amortization, or other events.

The entire disclosure for the aggregate amount of goodwill and a description of intangible assets, which may include (a) for amortizable intangible assets (also referred to as finite-lived intangible assets), the carrying amount, the amount of any significant residual value, and the weighted-average amortization period, (b) for intangible assets not subject to amortization (also referred to as indefinite-lived intangible assets), the carrying amount, and (c) the amount of research and development assets acquired and written off in the period, including the line item in the income statement in which the amounts written off are aggregated, if not readily apparent from the income statement. Also discloses (a) for amortizable intangibles assets in total and by major class, the gross carrying amount and accumulated amortization, the total amortization expense for the period, and the estimated aggregate amortization expense for each of the five succeeding fiscal years, (b) for intangible assets not subject to amortization the carrying amount in total and by major class, and (c) for goodwill, in total and for each reportable segment, the changes in the carrying amount of goodwill during the period (including the aggregate amount of goodwill acquired, the aggregate amount of impairment losses recognized, and the amount of goodwill included in the gain (loss) on disposal of a reporting unit). If any part of goodwill has not been allocated to a reportable segment, discloses the unallocated amount and the reasons for not allocating. For each impairment loss recognized related to an intangible asset (excluding goodwill), discloses: (a) a description of the impaired intangible asset and the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method for determining fair value, (c) the caption in the income statement or the statement of activities in which the impairment loss is aggregated, and (d) the segment in which the impaired intangible asset is reported. For each goodwill impairment loss recognized, discloses: (a) a description of the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method of determining the fair value of the associated reporting unit, and (c) if a recognized impairment loss is an estimate not finalized and the reasons why the estimate is not final. May also disclose the nature and amount of any significant adjustments made to a previous estimate of an impairment loss.

Compensation And Retirement Disclosure [Abstract]

Debt

6 Months Ended

Mar. 31, 2018

Debt Disclosure [Abstract]

Debt

NOTE H – DEBT

The following table summarizes Ashland’s current and long-term debt as of the dates reported in the Condensed Consolidated Balance Sheets.

(In millions)	March 31, 2018			September 30, 2017
4.750% notes, due 2022	$	1,082		$	1,082
Term Loan B, due 2024		596			599
6.875% notes, due 2043		376			376
Revolving Credit Facility		—			173
Term Loan A, due 2022		250			250
Term Loan A, due 2020		250			250
Accounts receivable securitization		48			56
6.50% junior subordinated notes, due 2029		51			51
Medium-term notes, due 2019, interest of 9.4%		5			5
Other (a)		(20	)		(23	)
Total debt		2,638			2,819
Short-term debt (includes current portion of long-term debt)		(59	)		(235	)
Long-term debt (less current portion)	$	2,579		$	2,584

(a)

Other includes $23 million and $25 million of debt issuance cost discounts as of March 31, 2018 and September 30, 2017, respectively.

The scheduled aggregate maturities of long-term debt by year (including the current portion and excluding debt issuance costs) are as follows: $3 million remaining in 2018, $11 million in 2019, $269 million in 2020, $56 million in 2021 and $1,279 million in 2022.

Ashland Financing Activities

Accounts receivable securitization

During March 2018, the termination date of the accounts receivable securitization facility was extended from March 2018 to March 2020. The available funding for qualified receivables under the accounts receivable securitization facility increased from $100 million to $115 million. No other changes to the agreement are expected to have a significant impact to Ashland's results of operations and financial position.

Cash repatriation

During January 2018, Ashland repatriated approximately $300 million in cash that was primarily used to repay the outstanding balance of the 2017 Revolving Credit Facility and a portion of the accounts receivable securitization during the current quarter.

2017 Credit Agreement

On May 17, 2017, in conjunction with the closing of the Pharmachem acquisition, Ashland entered into a secured credit agreement (the 2017 Credit Agreement) with a group of lenders. The 2017 Credit Agreement provided for (i) a $250 million three-year term loan A facility (the Three-Year TLA Facility), (ii) a $250 million five-year term loan A facility (the Five-Year TLA Facility and together with the Three-Year TLA Facility, the TLA Facilities) and (iii) a $680 million five-year revolving credit facility (including a $125 million letter of credit sublimit) (the 2017 Revolving Credit Facility). Proceeds of borrowings under the TLA Facilities were used solely to finance the acquisition of Pharmachem, while the proceeds of the 2017 Revolving Credit Facility were used to finance, in part, the acquisition of Pharmachem, to refinance the 2015 Senior Credit Agreement and for general corporate purposes. On May 19, 2017, Ashland entered into Amendment No. 1 to the 2017 Credit Agreement, which increased the aggregate commitments under the 2017 Revolving Credit Facility from $680 million to $800 million.

At Ashland’s option, loans issued under the 2017 Credit Agreement bear interest at either LIBOR or an alternate base rate, in each case plus the applicable interest rate margin. Loans bear interest at LIBOR plus 1.75% per annum, in the case of LIBOR borrowings, or at the alternate base rate plus 0.75%, in the alternative, through and including the date of delivery of a quarterly compliance certificate and thereafter the interest rate will fluctuate between LIBOR plus 1.375% per annum and LIBOR plus 2.500% per annum (or between the alternate base rate plus 0.375% per annum and the alternate base rate plus 1.500% per annum), based upon Ashland’s secured facilities ratings or the consolidated net leverage ratio (as defined in the 2017 Credit Agreement) (whichever yields a lower applicable interest rate margin) at such time. In addition, Ashland was required to pay fees of 0.25% per annum on the daily unused amount of the 2017 Revolving Credit Facility through and including the date of delivery of a compliance certificate, and thereafter the fee rate will fluctuate between 0.175% and 0.40% per annum, based upon Ashland’s secured facilities rating or the consolidated net leverage ratio (whichever yields a lower applicable rate). The TLA Facilities may be prepaid at any time without premium. The Three-Year TLA Facility will not amortize and will be due on May 17, 2020. The Five-Year TLA Facility will not amortize in each of the first, second and third years and will amortize at a rate of 20% per annum in each of the fourth and fifth years (payable in equal quarterly installments), with the outstanding balance of the Five-Year TLA Facility to be paid on May 17, 2022.

On June 14, 2017, Ashland entered into Amendment No. 2 to the 2017 Credit Agreement, which provided for a new $600 million seven-year senior secured term loan B facility (the 2017 TLB Facility). At Ashland’s option, loans issued under the 2017 TLB Facility bear interest at either (x) LIBOR plus 2.00% per annum or (y) an alternate base rate plus 1.00% per annum. The 2017 TLB Facility may be prepaid at any time. The 2017 TLB Facility amortizes at a rate of 1.00% per annum (payable in equal quarterly installments) with the outstanding balance to be paid on May 17, 2024.

6.50% junior subordinated notes due 2029

In December 2016, Hercules LLC (Hercules) (formerly Hercules Incorporated), an indirect wholly-owned subsidiary of Ashland, repurchased, through a cash tender offer (the Tender Offer), $182 million of the aggregate principal par value amount of its 6.50% junior subordinated notes due 2029 (2029 notes) for an aggregate purchase price of $177 million. As a result of the Tender Offer, the carrying value of the 2029 notes was reduced by $90 million and Ashland recognized a $92 million charge related to accelerated accretion of the recorded debt discount (compared to the total par value) and $5 million of a net gain related to the repayment of the debt. The charge and net gain are included in the net interest and other financing expense caption of the Statements of Consolidated Comprehensive Income (Loss) for the six months ended March 31, 2017.

Open market repurchases of 4.750% notes due 2022 and 3.875% notes due 2018

During the six months ended March 31, 2017, Ashland executed open market repurchases of its 4.750% notes due 2022 (2022 notes) and its 3.875% notes due 2018 (2018 notes). As a result of these repurchases, the carrying values of the 2022 notes and 2018 notes were reduced by $39 million and $41 million, respectively. Ashland recognized a $3 million charge related to premiums paid in the open market repurchases and accelerated amortization of previously capitalized debt issuance costs, which is included in the net interest and other financing expense caption of the Statements of Consolidated Comprehensive Income (Loss) for the six months ended March 31, 2017.

Remaining borrowing capacity

The borrowing capacity remaining under the 2017 Revolving Credit Facility was $752 million due to a reduction of $48 million for letters of credit outstanding at March 31, 2018. Ashland's total borrowing capacity at March 31, 2018 was $819 million, which included $67 million of available capacity from the accounts receivable securitization facility.

Covenants related to current Ashland debt agreements

Ashland's debt contains usual and customary representations, warranties and affirmative and negative covenants, including financial covenants for leverage and interest coverage ratios, limitations on liens, additional subsidiary indebtedness, restrictions on subsidiary distributions, investments, mergers, sale of assets and restricted payments and other customary limitations. As of March 31, 2018, Ashland is in compliance with all debt agreement covenant restrictions.

The maximum consolidated net leverage ratio permitted under Ashland's most recent credit agreement (the 2017 Credit Agreement) is 4.5. At March 31, 2018, Ashland’s calculation of the consolidated net leverage ratio was 3.8.

The minimum required consolidated interest coverage ratio under the 2017 Credit Agreement during its entire duration is 3.0. At March 31, 2018, Ashland’s calculation of the interest coverage ratio was 4.8.

Income Taxes

6 Months Ended

Mar. 31, 2018

Income Tax Disclosure [Abstract]

Income Taxes

NOTE I – INCOME TAXES

Tax Law Changes

The Tax Cuts and Jobs Act (Tax Act) was enacted on December 22, 2017. The Tax Act reduces the U.S. federal corporate tax rate from 35% to 21%, requires companies to pay a one-time transition tax on earnings of certain foreign subsidiaries that were previously tax deferred and creates new taxes on certain foreign sourced earnings. At March 31, 2018, Ashland has not completed the internal accounting assessment for the tax effects of enactment of the Tax Act; however, Ashland determined a reasonable estimate of the effects on our existing deferred tax balances and the one-time transition tax. Ashland recognized a provisional amount for the six months ended March 31, 2018, which is included as a component of income tax expense from continuing operations. Ashland recorded net unfavorable tax adjustments of $16 million during the six months ended March 31, 2018 primarily related to deferred tax rate changes and a one-time transition tax assessed on foreign cash and unremitted earnings.

Provisional amounts - Deferred and other income tax assets and liabilities

Ashland remeasured certain deferred tax assets and liabilities based on the rates at which they are expected to reverse in the future, which is generally 21%. However, Ashland is still analyzing certain aspects of the Tax Act and refining certain calculations, which could potentially affect the measurement of these balances or potentially give rise to new deferred tax amounts. The provisional amount recorded related to the remeasurement of the deferred tax balance was a favorable tax adjustment of $126 million during the six months ended March 31, 2018.

Provisional amounts - Foreign tax effects

The one-time transition tax is based on Ashland's total post-1986 earnings and profits (E&P) of foreign subsidiaries that were previously deferred from U.S. income taxes. Ashland recorded a provisional amount for this one-time transition tax liability of $142 million during the six months ended March 31, 2018, which is primarily included within the other liabilities caption on the Condensed Consolidated Balance Sheet. Ashland has not yet completed its calculation of the total post-1986 E&P for these foreign subsidiaries. In addition, the transition tax is based in part on the amount of those earnings held in cash and other specified assets. This amount may change when Ashland finalizes the calculation of post-1986 foreign E&P previously deferred from U.S. federal taxation and finalizes the amounts held in cash or other specified assets. No additional income taxes have been provided for any remaining undistributed foreign earnings not subject to the transition tax, or any additional outside basis difference inherent in these entities, as these amounts continue to be indefinitely reinvested in foreign operations. Ashland determined that the amount of unrecognized deferred tax liability related to any remaining undistributed foreign earnings not subject to the transition tax and additional outside basis difference in these entities (i.e., basis difference in excess of that subject to the one-time transition tax) is not practicable at this time.

Current fiscal year

Ashland’s effective tax rate in any interim period is subject to adjustments related to discrete items and the mix of domestic and foreign operating results. The overall effective tax rate was 1% and 20% for the three and six months ended March 31, 2018, respectively. The current quarter tax rate was primarily impacted by income mix and a favorable tax discrete adjustment of $4 million related to a deferred tax rate change for a foreign entity. In addition to these current quarter items, the current six month period tax rate was significantly impacted by net unfavorable tax discrete adjustments of $16 million related to the Tax Act.

Prior fiscal year

The overall effective tax rate was a benefit of 21% for the three months ended March 31, 2017 and 55% for the six months ended March 31, 2017. The prior quarter and six month period tax rate was impacted by income mix and net favorable tax discrete items of $4 million primarily related to unrecognized tax benefits due to lapse of the statute of limitations.

Unrecognized tax benefits

Changes in unrecognized tax benefits are summarized as follows for the six months ended March 31, 2018.

(In millions)
Balance at October 1, 2017	$	194
Increases related to positions taken on items from prior years		3
Decreases related to positions taken on items from prior years		(1	)
Increases related to positions taken in the current year		6
Lapse of statute of limitations		(1	)
Balance at March 31, 2018	$	201

From a combination of statute expirations and audit settlements in the next twelve months, Ashland expects a decrease in the amount accrued for uncertain tax positions of between $21 million and $31 million for continuing operations. It is reasonably possible that there could be other material changes to the amount of uncertain tax positions due to activities of the taxing authorities, settlement of audit issues or the reassessment of existing uncertain tax positions; however, Ashland is not able to estimate the impact of these items at this time.

Employee Benefit Plans

6 Months Ended

Mar. 31, 2018

Employee Benefit Plans

NOTE J - EMPLOYEE BENEFIT PLANS

For the six months ended March 31, 2018, Ashland contributed $6 million to its non-U.S. pension plans and $1 million to its U.S. pension plans. Ashland expects to make additional contributions of approximately $2 million to its non-U.S. plans during the remainder of 2018.

Plan Remeasurements

Effective January 1, 2017, Ashland discontinued certain post-employment health and life insurance benefits. The effect of these plan changes resulted in a remeasurement gain of $2 million recorded within the other net period benefit income caption on the Statement of Consolidated Comprehensive Income (Loss) for the six months ended March 31, 2017.

Components of net periodic benefit costs (income)

The following table details the components of pension and other postretirement benefit costs for continuing operations.

	Pension benefits						Other postretirement benefits
(In millions)	2018			2017			2018		2017
Three months ended March 31
Service cost (a)	$	2		$	2		$	—	$	—
Interest cost (b)		2			2			—		—
Expected return on plan assets (b)		(3	)		(2	)		—		—
Total net periodic benefit costs	$	1		$	2		$	—	$	—
Six months ended March 31
Service cost (a)	$	4		$	4		$	1	$	—
Interest cost (b)		5			4			—		1
Expected return on plan assets (b)		(6	)		(6	)		—		—
Actuarial gain (b)		—			—			—		(2	)
Total net periodic benefit costs (income)	$	3		$	2		$	1	$	(1	)

(a)

Service cost was not impacted by new accounting guidance adopted in 2018 and is therefore still classified within the selling, general and administrative expense and cost of sales captions on the Statements of Consolidated Comprehensive Income (Loss). See Note A for additional information.

(b)

These components are now classified within the other net periodic benefit income caption on the Statements of Consolidated Comprehensive Income (Loss) due to the adoption of new accounting guidance in the current quarter. See Note A for additional information.

For segment reporting purposes, service cost for continuing operations is proportionately allocated to each segment, excluding the Unallocated and other segment, while all other costs for continuing operations are recorded within the other net periodic benefit income caption on the Statements of Consolidated Comprehensive Income (Loss).

Litigation, Claims and Contingencies

6 Months Ended

Mar. 31, 2018

Commitments And Contingencies Disclosure [Abstract]

Litigation, Claims and Contingencies

NOTE K – LITIGATION, CLAIMS AND CONTINGENCIES

Asbestos litigation

Ashland and Hercules have liabilities from claims alleging personal injury caused by exposure to asbestos. To assist in developing and annually updating independent reserve estimates for future asbestos claims and related costs given various assumptions, Ashland retained third party actuarial experts. Prior to 2018, Ashland retained Hamilton, Rabinovitz & Associates, Inc. (HR&A). During 2018, Ashland transitioned these responsibilities to Nathan Associates, Inc. (Nathan). The processes and methodologies used by Nathan are similar to the ones historically employed by HR&A. The methodology used by Nathan to project future asbestos costs is based largely on recent experience, including claim-filing and settlement rates, disease mix, enacted legislation, open claims and litigation defense. The claim experience of Ashland and Hercules are separately compared to the results of previously conducted third party epidemiological studies estimating the number of people likely to develop asbestos-related diseases. Those studies were undertaken in connection with national analyses of the population expected to have been exposed to asbestos. Using that information, Nathan estimates a range of the number of future claims that may be filed, as well as the related costs that may be incurred in resolving those claims. Changes in asbestos-related liabilities and receivables are recorded on an after-tax basis within the discontinued operations caption in the Statements of Consolidated Comprehensive Income (Loss).

Ashland asbestos-related litigation

The claims alleging personal injury caused by exposure to asbestos asserted against Ashland result primarily from indemnification obligations undertaken in 1990 in connection with the sale of Riley. The amount and timing of settlements and number of open claims can fluctuate from period to period. A summary of Ashland asbestos claims activity, excluding Hercules claims, follows.

	Six months ended
	March 31						Years ended September 30
(In thousands)	2018			2017			2017			2016			2015
Open claims - beginning of year		54			57			57			60			65
New claims filed		1			1			2			2			2
Claims settled		—			—			(1	)		—			—
Claims dismissed		(2	)		(2	)		(4	)		(5	)		(7	)
Open claims - end of period		53			56			54			57			60

Ashland asbestos-related liability

During the most recent annual update of this estimate completed during the June 2017 quarter, it was determined that the liability for Ashland asbestos-related claims should be increased by $36 million. Total reserves for asbestos claims were $402 million at March 31, 2018 compared to $419 million at September 30, 2017.

A progression of activity in the asbestos reserve is presented in the following table.

	Six months ended
	March 31						Years ended September 30
(In millions)	2018			2017			2017			2016			2015
Asbestos reserve - beginning of year	$	419		$	415		$	415		$	409		$	438
Reserve adjustment		—			—			36			37			—
Amounts paid		(17	)		(18	)		(32	)		(31	)		(29	)
Asbestos reserve - end of period (a)	$	402		$	397		$	419		$	415		$	409

(a)

Included $34 million classified in accrued expenses and other liabilities on the Condensed Consolidated Balance Sheets as of March 31, 2018 and September 30, 2017.

Ashland asbestos-related receivables

Ashland has insurance coverage for certain litigation defense and claim settlement costs incurred in connection with its asbestos claims, and coverage-in-place agreements exist with the insurance companies that provide substantially all of the coverage that will be accessed.

For the Ashland asbestos-related obligations, Ashland has estimated the value of probable insurance recoveries associated with its asbestos reserve based on management’s interpretations and estimates surrounding the available or applicable insurance coverage, including an assumption that all solvent insurance carriers remain solvent. Substantially all of the estimated receivables from insurance companies are expected to be due from domestic insurers, all of which are solvent.

At March 31, 2018, Ashland’s receivable for recoveries of litigation defense and claim settlement costs from insurers amounted to $149 million (excluding the Hercules receivable for asbestos claims) compared to $155 million at September 30, 2017. During the June 2017 quarter, the annual update of the model used for purposes of valuing the asbestos reserve and its impact on valuation of future recoveries from insurers was completed. This model update resulted in a $15 million increase in the receivable for probable insurance recoveries.

A progression of activity in the Ashland insurance receivable is presented in the following table.

	Six months ended
	March 31						Years ended September 30
(In millions)	2018			2017			2017			2016			2015
Insurance receivable - beginning of year	$	155		$	151		$	151		$	150		$	402
Receivable adjustment		—			—			15			16			(3	)
Insurance settlement		—			(5	)		(5	)		(4	)		(227	)
Amounts collected		(6	)		(2	)		(6	)		(11	)		(22	)
Insurance receivable - end of period (a)	$	149		$	144		$	155		$	151		$	150

(a)

Included $14 million classified in accounts receivable on the Condensed Consolidated Balance Sheets as of March 31, 2018 and September 30, 2017.

Hercules asbestos-related litigation

Hercules has liabilities from claims alleging personal injury caused by exposure to asbestos. Such claims typically arise from alleged exposure to asbestos fibers from resin encapsulated pipe and tank products which were sold by one of Hercules’ former subsidiaries to a limited industrial market. The amount and timing of settlements and number of open claims can fluctuate from period to period. A summary of Hercules’ asbestos claims activity follows.

	Six months ended
	March 31						Years ended September 30
(In thousands)	2018			2017			2017			2016			2015
Open claims - beginning of year		12			15			15			20			21
New claims filed		1			1			1			1			1
Claims dismissed		(1	)		(3	)		(4	)		(6	)		(2	)
Open claims - end of period		12			13			12			15			20

Hercules asbestos-related liability

From the range of estimates, Ashland records the amount it believes to be the best estimate of future payments for litigation defense and claim settlement costs, which generally approximates the mid-point of the estimated range of exposure from model results. Ashland reviews this estimate and related assumptions quarterly and annually updates the results of a non-inflated, non-discounted approximate 50-year model developed with the assistance of Nathan. As a result of the most recent annual update of this estimate, completed during the June 2017 quarter, it was determined that the liability for Hercules asbestos-related claims should be increased by $16 million. Total reserves for asbestos claims were $311 million at March 31, 2018 compared to $323 million at September 30, 2017.

A progression of activity in the asbestos reserve is presented in the following table.

	Six months ended
	March 31						Years ended September 30
(In millions)	2018			2017			2017			2016			2015
Asbestos reserve - beginning of year	$	323		$	321		$	321		$	311		$	329
Reserve adjustments		—			—			16			25			4
Amounts paid		(12	)		(5	)		(14	)		(15	)		(22	)
Asbestos reserve - end of period (a)	$	311		$	316		$	323		$	321		$	311

(a)

Included $14 million classified in accrued expenses and other liabilities on the Condensed Consolidated Balance Sheets as of March 31, 2018 and September 30, 2017.

Hercules asbestos-related receivables

For the Hercules asbestos-related obligations, certain reimbursement obligations pursuant to coverage-in-place agreements with insurance carriers exist. As a result, any increases in the asbestos reserve have been partially offset by probable insurance recoveries. Ashland has estimated the value of probable insurance recoveries associated with its asbestos reserve based on management’s interpretations and estimates surrounding the available or applicable insurance coverage, including an assumption that all solvent insurance carriers remain solvent. The estimated receivable consists exclusively of solvent domestic insurers.

As of March 31, 2018 and September 30, 2017, the receivables from insurers amounted to $68 million. During the June 2017 quarter, the annual update of the model used for purposes of valuing the asbestos reserve and its impact on valuation of future recoveries from insurers was completed. This model update resulted in a $5 million increase in the receivable for probable insurance recoveries.

A progression of activity in the Hercules insurance receivable is presented in the following table.

	Six months ended
	March 31				Years ended September 30
(In millions)	2018		2017		2017		2016		2015
Insurance receivable - beginning of year	$	68	$	63	$	63	$	56	$	77
Receivable adjustment		—		—		5		7		1
Insurance settlement		—		—		—		—		(22	)
Insurance receivable - end of period	$	68	$	63	$	68	$	63	$	56

Asbestos litigation cost projection

Projecting future asbestos costs is subject to numerous variables that are extremely difficult to predict. In addition to the significant uncertainties surrounding the number of claims that might be received, other variables include the type and severity of the disease alleged by each claimant, the long latency period associated with asbestos exposure, mortality rates, dismissal rates, costs of medical treatment, the impact of bankruptcies of other companies that are co-defendants in claims, uncertainties surrounding the litigation process from jurisdiction to jurisdiction and from case to case, and the impact of potential changes in legislative or judicial standards. Furthermore, any predictions with respect to these variables are subject to even greater uncertainty as the projection period lengthens. Considering these inherent uncertainties, Ashland believes that the asbestos reserves for Ashland and Hercules represent the best estimate within a range of possible outcomes. As a part of the process to develop these estimates of future asbestos costs, a range of long-term cost models was developed. These models are based on national studies that predict the number of people likely to develop asbestos-related diseases and are heavily influenced by assumptions regarding long-term inflation rates for indemnity payments and legal defense costs, as well as other variables mentioned previously. Ashland has currently estimated in various models ranging from approximately 40 to 50 year periods that it is reasonably possible that total future litigation defense and claim settlement costs on an inflated and undiscounted basis could range as high as approximately $660 million for the Ashland asbestos-related litigation (current reserve of $402 million) and approximately $510 million for the Hercules asbestos-related litigation (current reserve of $311 million), depending on the combination of assumptions selected in the various models. If actual experience is worse than projected, relative to the number of claims filed, the severity of alleged disease associated with those claims or costs incurred to resolve those claims, or actuarial refinement or improvements to the assumptions used within these models are initiated, Ashland may need to further increase the estimates of the costs associated with asbestos claims and these increases could be material over time.

Environmental remediation and asset retirement obligations

Ashland is subject to various federal, state and local environmental laws and regulations that require environmental assessment or remediation efforts (collectively environmental remediation) at multiple locations. At March 31, 2018, such locations included 83 waste treatment or disposal sites where Ashland has been identified as a potentially responsible party under Superfund or similar state laws, 117 current and former operating facilities (including certain operating facilities conveyed as part of the MAP Transaction) and about 1,225 service station properties, of which 36 are being actively remediated.

Ashland’s reserves for environmental remediation and related environmental litigation amounted to $164 million at March 31, 2018 compared to $163 million at September 30, 2017, of which $122 million at March 31, 2018 and $121 million at September 30, 2017 were classified in other noncurrent liabilities on the Condensed Consolidated Balance Sheets. The remaining reserves were classified in accrued expenses and other liabilities on the Condensed Consolidated Balance Sheets.

The following table provides a reconciliation of the changes in the environmental remediation reserves during the six months ended March 31, 2018 and 2017.

	Six months ended
	March 31
(In millions)	2018			2017
Reserve - beginning of period	$	163		$	177
Disbursements		(16	)		(15	)
Revised obligation estimates and accretion		17			5
Reserve - end of period	$	164		$	167

The total reserves for environmental remediation reflect Ashland’s estimates of the most likely costs that will be incurred over an extended period to remediate identified conditions for which the costs are reasonably estimable, without regard to any third-party recoveries. Engineering studies, probability techniques, historical experience and other factors are used to identify and evaluate remediation alternatives and their related costs in determining the estimated reserves for environmental remediation. Ashland continues to discount certain environmental sites and regularly adjusts its reserves as environmental remediation continues. Ashland has estimated the value of its probable insurance recoveries associated with its environmental reserve based on management’s interpretations and estimates surrounding the available or applicable insurance coverage. At March 31, 2018 and September 30, 2017, Ashland’s recorded receivable for these probable insurance recoveries was $14 million and $15 million, respectively, of which $13 million at March 31, 2018 and $14 million at September 30, 2017 were classified in other noncurrent assets on the Condensed Consolidated Balance Sheets.

Components of environmental remediation expense included within the selling, general and administrative expense caption of the Statements of Consolidated Comprehensive Income (Loss) are presented in the following table for the three and six months ended March 31, 2018 and 2017.

	Three months ended					Six months ended
	March 31					March 31
(In millions)	2018			2017		2018			2017
Environmental expense	$	4		$	1	$	16		$	5
Accretion		—			—		1			—
Legal expense		2			4		3			5
Total expense		6			5		20			10

Insurance receivable (a)		(1	)		—		(1	)		—
Total expense, net of receivable activity (b)	$	5		$	5	$	19		$	10

(a)

Activity of $0 denotes value less than $1 million.

(b)

Net expense of $1 million for both the three and six months ended March 31, 2018, and $1 million and $2 million for the three and six months ended March 31, 2017, respectively, relates to divested businesses which qualified for treatment as discontinued operations and for which certain environmental liabilities were retained by Ashland. These amounts are classified within the income from discontinued operations caption of the Statements of Consolidated Comprehensive Income (Loss).

Environmental remediation reserves are subject to numerous inherent uncertainties that affect Ashland’s ability to estimate its share of the costs. Such uncertainties involve the nature and extent of contamination at each site, the extent of required cleanup efforts under existing environmental regulations, widely varying costs of alternate cleanup methods, changes in environmental regulations, the potential effect of continuing improvements in remediation technology, and the number and financial strength of other potentially responsible parties at multiparty sites. Although it is not possible to predict with certainty the ultimate costs of environmental remediation, Ashland currently estimates that the upper end of the reasonably possible range of future costs for identified sites could be as high as approximately $409 million. The largest reserve for any site is approximately 15% of the remediation reserve.

Other legal proceedings and claims

In addition to the matters described above, there are other various claims, lawsuits and administrative proceedings pending or threatened against Ashland and its current and former subsidiaries. Such actions are with respect to commercial matters, product liability, toxic tort liability, and other environmental matters, which seek remedies or damages, some of which are for substantial amounts. While Ashland cannot predict with certainty the outcome of such actions, it believes that adequate reserves have been recorded and losses already recognized with respect to such actions were immaterial as of March 31, 2018 and September 30, 2017. There is a reasonable possibility that a loss exceeding amounts already recognized may be incurred related to these actions; however, Ashland believes that such potential losses were immaterial as of March 31, 2018.

Earnings Per Share

6 Months Ended

Mar. 31, 2018

Earnings Per Share [Abstract]

Earnings Per Share

NOTE L – EARNINGS PER SHARE

The following is the computation of basic and diluted earnings per share (EPS) from continuing operations attributable to Ashland. Stock appreciation rights (SARs), stock options and warrants available to purchase shares outstanding for each reporting period whose grant price was greater than the average market price of Ashland Common Stock for each applicable period were not included in the computation of income from continuing operations per diluted share because the effect of these instruments would be antidilutive. The total number of these shares outstanding was approximately 0.7 million and 0.1 million at March 31, 2018 and 2017, respectively. Earnings per share is reported under the treasury stock method.

	Three months ended				Six months ended
	March 31				March 31
(In millions, except per share data)	2018		2017		2018		2017
Numerator
Numerator for basic and diluted EPS -
Income (loss) from continuing operations	$	66	$	29	$	59	$	(37	)
Denominator
Denominator for basic EPS - Weighted-average
common shares outstanding		63		62		63		62
Share based awards convertible to common shares (a)		1		1		1		—
Denominator for diluted EPS - Adjusted weighted-
average shares and assumed conversions		64		63		64		62

EPS from continuing operations
Basic	$	1.06	$	0.46	$	0.94	$	(0.59	)
Diluted		1.04		0.46		0.93		(0.59	)

(a)

As a result of the loss from continuing operations attributable to Ashland during the six months ended March 31, 2017, the effect of the share-based awards convertible to common shares would be antidilutive. In accordance with U.S. GAAP, they have been excluded from the diluted EPS calculation.

Equity Items

6 Months Ended

Mar. 31, 2018

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Equity Items

NOTE M – EQUITY ITEMS

Stock repurchase programs

In April 2015, Ashland's Board of Directors approved a $1 billion share repurchase authorization that was set to expire on December 31, 2017 (the 2015 stock repurchase program). During September 2017, Ashland's Board of Directors extended the 2015 stock repurchase program indefinitely, at which point $500 million of share repurchase authorization remained under the 2015 stock repurchase program.

During March 2018, Ashland’s Board of Directors approved a new $1 billion stock repurchase program, which replaced the 2015 stock repurchase program. Under the new program, Ashland’s common shares may be repurchased in open market transactions, privately negotiated transactions or pursuant to one or more accelerated stock repurchase programs or Rule 10b5-1 plans. As of March 31, 2018, $1 billion remained available for repurchase under this authorization.

Stockholder dividends

In May 2017, subsequent to the final distribution of Valvoline Inc.'s common stock, the Board of Directors of Ashland announced a quarterly cash dividend of 22.5 cents per share to eligible stockholders at record which was paid for quarterly dividends in the first and second quarters of fiscal 2018 and the third and fourth quarters of fiscal 2017. This represented a reduction from the previous quarterly dividend of 39 cents per share which was paid for quarterly dividends in the first and second quarters of fiscal 2017.

Accumulated other comprehensive income (loss)

Components of other comprehensive income (loss) recorded in the Statements of Consolidated Comprehensive Income (Loss) are presented below, before tax and net of tax effects.

	2018									2017
(In millions)	Before tax			Tax (expense) benefit			Net of tax			Before tax			Tax (expense) benefit			Net of tax
Three months ended March 31
Other comprehensive income (loss)
Unrealized translation gain	$	55		$	—		$	55		$	58		$	2		$	60
Amortization of unrecognized prior
service credit (a)		—			—			—			(3	)		1			(2	)
Net change in available-for-sale securities:
Unrealized loss		(5	)		1			(4	)		9			(2	)		7
Reclassification adjustment for gains
included in net income		(3	)		1			(2	)		(2	)		1			(1	)
Total other comprehensive income	$	47		$	2		$	49		$	62		$	2		$	64

Six months ended March 31
Other comprehensive income (loss)
Unrealized translation gain (loss)	$	58		$	—		$	58		$	(92	)	$	6		$	(86	)
Amortization of unrecognized prior
service credit (a)		—			—			—			(6	)		2			(4	)
Net change in available-for-sale securities:
Unrealized gain		6			(1	)		5			9			(2	)		7
Reclassification adjustment for gains
included in net income		(4	)		1			(3	)		(2	)		1			(1	)
Total other comprehensive income (loss)	$	60		$	—		$	60		$	(91	)	$	7		$	(84	)

(a)

For the three and six months ended March 31, 2017, the amortization of unrecognized prior services credits was related to pension and other postretirement benefit plans that transferred to Valvoline and was classified within the discontinued operations caption on the Statements of Consolidated Comprehensive Income (Loss).

Stock Incentive Plans

6 Months Ended

Mar. 31, 2018

Stock Incentive Plans

NOTE N – STOCK INCENTIVE PLANS

Ashland has stock incentive plans under which key employees or directors are granted stock appreciation rights (SARs), performance awards or nonvested stock awards. Each program is typically a long-term incentive plan designed to link employee compensation with increased shareholder value or reward superior performance and encourage continued employment with Ashland. Ashland recognizes compensation expense for the grant date fair value of stock-based awards over the applicable vesting period.

The components of Ashland’s pretax stock-based compensation expense included in continuing operations are as follows:

	Three months ended				Six months ended
	March 31				March 31
(In millions)	2018 (a)		2017 (b)		2018 (a)		2017 (b)
SARs	$	2	$	2	$	3	$	3
Nonvested stock awards		5		3		11		7
Performance share awards		2		2		6		4
	$	9	$	7	$	20	$	14

(a)

Included $2 million and $4 million of expense related to cash-settled nonvested restricted stock awards and $1 million and $3 million of expense related to cash-settled performance units during the three and six months ended March 31, 2018, respectively.

(b)

Included $2 million and $3 million of expense related to cash-settled nonvested restricted stock awards and $1 million and $2 million of expense related to cash-settled performance units during the three and six months ended March 31, 2017, respectively.

SARs

SARs are granted to employees or directors at a price equal to the fair market value of the stock on the date of grant and typically become exercisable over periods of one to three years. Unexercised SARs lapse ten years and one month after the date of grant. No SARs granted for the three months ended March 31, 2018 and 2017. SARs granted for the six months ended March 31, 2018 and 2017 were 470 thousand and 422 thousand, respectively. As of March 31, 2018, there was $11 million of total unrecognized compensation costs related to SARs. That cost is expected to be recognized over a weighted-average period of 2.2 years. Ashland estimates the fair value of SARs granted using the Black-Scholes option-pricing model. This model requires several assumptions, which Ashland has developed and updates based on historical trends and current market observations. The accuracy of these assumptions is critical to the estimate of fair value for these equity instruments.

Nonvested stock awards

Nonvested stock awards are granted to employees or directors at a price equal to the fair market value of the stock on the date of grant and generally vest over a one-to-five-year period. However, such shares or units are subject to forfeiture upon termination of service before the vesting period ends. Only nonvested stock awards granted in the form of shares entitle employees or directors to vote the shares. Dividends on nonvested stock awards granted are in the form of additional units or shares of nonvested stock awards, which are subject to vesting and forfeiture provisions.

Stock-settled nonvested stock awards

Nonvested stock awards granted in the form of shares were 2 thousand and 3 thousand for the three months ended March 31, 2018 and 2017, respectively, and 144 thousand and 84 thousand for the six months ended March 31, 2018 and 2017, respectively. As of March 31, 2018, there was $10 million of total unrecognized compensation costs related to these nonvested stock awards. That cost is expected to be recognized over a weighted-average period of 2.0 years.

Cash-settled nonvested stock awards

Certain nonvested stock awards are granted to employees and are settled in cash upon vesting. As of March 31, 2018, 229 thousand cash-settled nonvested stock awards were outstanding. The value of these cash-settled nonvested stock awards changes in connection with changes in the fair market value of the Ashland Common Stock. These awards generally vest over a period of three years. The expense recognized related to cash-settled nonvested stock awards was $2 million during both the three months ended March 31, 2018 and 2017, and $4 million and $3 million during the six months ended March 31, 2018 and 2017, respectively.

Executive performance incentive and retention program

During 2016, certain executives were granted performance-based restricted shares of Ashland in order to provide an incentive to remain employed in the period after the full separation. At March 31, 2018, there were 61 thousand shares outstanding in connection with these awards, which includes forfeitures and the cumulative value of forfeitable dividends. The expense recognition for these awards commenced upon completing the full separation of Valvoline which occurred on May 12, 2017, as discussed further in Note B, and resulted in $1 million and $3 million of expense for the three and six months ended March 31, 2018, respectively. As of March 31, 2018, there was $6 million of total unrecognized compensation costs related to these awards.

Performance awards

Ashland sponsors a long-term incentive plan that awards performance shares/units to certain key employees that are primarily tied to Ashland’s overall financial performance relative to internal targets. Additionally, certain outstanding performance awards are tied to Ashland's overall financial performance relative to the financial performance of selected industry peer groups. Awards are granted annually, with each award covering a three-year vesting period.

For awards granted in fiscal 2016, each performance share/unit is convertible to one share of Ashland Common Stock. These plans are recorded as a component of stockholders’ equity in the Condensed Consolidated Balance Sheets. Performance measures used to determine the actual number of performance shares issuable upon vesting include an equal weighting of Ashland’s total shareholder return (TSR) performance and Ashland’s return on investment (ROI) performance as compared to the internal targets. TSR relative to peers is considered a market condition while ROI is considered a performance condition under applicable U.S. GAAP.

For awards granted in fiscal 2017 and 2018, the performance measure used to determine the actual number of performance shares/units issuable upon vesting is the financial performance of Ashland compared to award targets. The financial performance award metric is considered a performance condition under applicable U.S. GAAP. Additionally, the actual number of performance shares/units issuable upon vesting can be potentially increased or decreased based on a TSR performance modifier relative to peers of Ashland. For awards granted in fiscal 2017, each performance unit will be settled in cash based on the fair value of Ashland common stock. For awards granted in fiscal 2018, each performance share/unit is convertible to one share of Ashland Common Stock.

Nonvested performance shares/units do not entitle employees to vote the shares or to receive any dividends thereon. No performance shares/units were granted for the three months ended March 31, 2018 and 2017. Performance shares/units granted for the six months ended March 31, 2018 and 2017 were 101 thousand and 56 thousand, respectively. As of March 31, 2018, there was $15 million of total unrecognized compensation costs related to performance shares/units. That cost is expected to be recognized over a weighted-average period of 2.0 years.

Reportable Segment Information

6 Months Ended

Mar. 31, 2018

Segment Reporting [Abstract]

Reportable Segment Information

NOTE O – REPORTABLE SEGMENT INFORMATION

Ashland determines its reportable segments based on how operations are managed internally for the products and services sold to customers, including how the results are reviewed by the chief operating decision maker, which includes determining resource allocation methodologies used for reportable segments. Operating income is the primary measure on the Statements of Consolidated Comprehensive Income (Loss) that is reviewed by the chief operating decision maker in assessing each reportable segment's financial performance. Ashland does not aggregate operating segments to arrive at these reportable segments.

Change in Reportable Segments

Subsequent to completing the separation from Valvoline Inc. on May 12, 2017, Ashland's operations are managed by the chief operating decision maker within the following three reportable segments: Specialty Ingredients, Composites and Intermediates and Solvents. As a result, the financial information for the new reportable segments (Composites and Intermediates and Solvents) has been disclosed for all periods presented. Prior to the separation from Valvoline Inc., Composites and Intermediates and Solvents were reporting units included within the previous Ashland Performance Materials reportable segment.

Reportable segment business descriptions

Specialty Ingredients is a global leader in cellulose ethers, vinyl pyrrolidones and biofunctionals. It offers industry-leading products, technologies and resources for solving formulation and product-performance challenges. Specialty Ingredients uses natural, synthetic and semisynthetic polymers derived from cellulose ethers, vinyl pyrrolidones, acrylic polymers, polyester and polyurethane-based adhesives, and plant and seed extract. Specialty Ingredients’ end markets offer comprehensive and innovative solutions for today’s demanding consumer and industrial applications. Key customers include: pharmaceutical companies; makers of personal care products, food and beverages; makers of nutraceuticals and supplements; manufacturers of paint, coatings and construction materials; packaging and converting; and oilfield service companies. On May 17, 2017, Ashland completed its acquisition of the stock of Pharmachem, a leading provider of quality ingredients to the global health and wellness industries and high-value differentiated products to fragrance and flavor houses. With 14 manufacturing facilities in the United States and Mexico, New Jersey-based Pharmachem develops, manufactures and supplies custom and branded nutritional and fragrance products. See Note C for more information.

Composites is a global leader in unsaturated polyester resins, vinyl ester resins and gelcoats. The Composites business manufactures and sells a broad range of general-purpose and high-performance grades of unsaturated polyester and vinyl ester resins, gelcoats and low-profile additives for the reinforced plastics industry. The products in the Composites business provide an array of functional properties including corrosion resistance, fire retardance, ultraviolet resistance, water and chemical resistance, high mechanical strength, impact and scratch resistance and high strength-to-weight ratios. Key end markets include transportation, construction, marine and infrastructure. In addition, the business manufactures and sells molten maleic anhydride for the manufacture of a variety of products such as unsaturated polyester resins, copolymers, lubricating oil additives, alkenyl succinic anhydrides, malic acid, fumaric acid and numerous derivative chemicals. Key markets include composites, personal care, dispersants and paper sizing.

Intermediates and Solvents is a leading producer of 1,4 butanediol (BDO) and related derivatives, including tetrahydrofuran and n-methylpyrrolidone. These products are used as chemical intermediates in the production of engineering polymers and polyurethanes, and as specialty process solvents in a wide array of applications including electronics, pharmaceuticals, water filtration membranes and more. Butanediol is also supplied to Ashland’s Specialty Ingredients business for use as a raw material.

Unallocated and Other generally includes items such as certain significant company-wide restructuring activities, including internal separation costs, and legacy costs or adjustments that relate to divested businesses that are no longer operated by Ashland.

Reportable segment results

Results of Ashland’s reportable segments are presented based on its management and internal accounting structure. The structure is specific to Ashland; therefore, the financial results of Ashland’s reportable segments are not necessarily comparable with similar information for other comparable companies. Ashland allocates all significant costs to its reportable segments except for certain significant company-wide restructuring activities and other costs or adjustments that relate to former businesses that Ashland no longer operates. The service cost component of pension and other postretirement benefits costs is allocated to each reportable segment on a ratable basis; while the remaining components of pension and other postretirement benefits costs are recorded within the other net periodic benefit income caption on the Statements of Consolidated Comprehensive Income (Loss). Ashland refines its expense allocation methodologies to the reportable segments from time to time as internal accounting practices are improved, more refined information becomes available and the industry or market changes. Significant revisions to Ashland’s methodologies are adjusted for all segments on a retrospective basis.

The following table presents various financial information for each reportable segment for the three and six months ended March 31, 2018 and 2017.

	Three months ended						Six months ended
	March 31						March 31
(In millions - unaudited)	2018			2017			2018			2017
SALES
Specialty Ingredients	$	646		$	544		$	1,196		$	1,026
Composites		238			186			456			351
Intermediates and Solvents		90			76			164			133
	$	974		$	806		$	1,816		$	1,510
OPERATING INCOME (LOSS)
Specialty Ingredients	$	89		$	74		$	131		$	114
Composites		19			13			36			29
Intermediates and Solvents		4			(3	)		13			(11	)
Unallocated and other		(17	)		(31	)		(47	)		(64	)
	$	95		$	53		$	133		$	68

Significant Accounting Policies (Policies)	6 Months Ended
Significant Accounting Policies (Policies)	Mar. 31, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation	Basis of presentation The accompanying unaudited Condensed Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States for interim financial reporting and Securities and Exchange Commission (SEC) regulations. In the opinion of management, all adjustments considered necessary for a fair presentation have been included. Additionally, certain prior period data, primarily related to discontinued operations, have been reclassified in the Consolidated Financial Statements and accompanying notes to conform to the current period presentation, as further described in this section. These statements omit certain information and footnote disclosures required for complete annual financial statements and, therefore, should be read in conjunction with Ashland’s Annual Report on Form 10-K for the fiscal year ended September 30, 2017. Results of operations for the period ended March 31, 2018 are not necessarily indicative of the expected results for the remaining quarters in the fiscal year. On May 12, 2017, Ashland completed the distribution of its remaining 170 million shares of common stock of Valvoline Inc. which represented approximately 83% of the total outstanding shares of Valvoline Inc.'s common stock. This separation from Valvoline represented a strategic shift in Ashland's business and qualified as a discontinued operation. Accordingly, Valvoline's operating results and cash flows for the three and six months ended March 31, 2017 have been classified as discontinued operations within the Condensed Consolidated Financial Statements. See Note B for additional information on the separation of Valvoline Inc. Subsequent to completing the separation from Valvoline Inc., Ashland's operations are managed within the following three reportable segments: Specialty Ingredients, Composites and Intermediates and Solvents.
Use of Estimates, Risk and Uncertainties	Use of estimates, risks and uncertainties The preparation of Ashland’s Condensed Consolidated Financial Statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and the disclosures of contingent assets and liabilities. Significant items that are subject to such estimates and assumptions include, but are not limited to, long-lived assets (including goodwill and other intangible assets), income taxes and liabilities and receivables associated with asbestos litigation and environmental remediation. Although management bases its estimates on historical experience and various other assumptions that are believed to be reasonable under the circumstances, actual results could differ significantly from the estimates under different assumptions or conditions. Ashland’s results are affected by domestic and international economic, political, legislative, regulatory and legal actions. Economic conditions, such as recessionary trends, inflation, interest and monetary exchange rates, government fiscal policies and changes in the prices of certain key raw materials, can have a significant effect on operations. While Ashland maintains reserves for anticipated liabilities and carries various levels of insurance, Ashland could be affected by civil, criminal, regulatory or administrative actions, claims or proceedings relating to asbestos, environmental remediation or other matters.
New Accounting Standards	New accounting standards A description of new U.S. GAAP accounting standards issued or adopted during the current year is required in interim financial reporting. A detailed listing of new accounting standards relevant to Ashland is included in the Annual Report on Form 10-K for the fiscal year ended September 30, 2017. The following standards relevant to Ashland were either issued or adopted in the current period, or will become effective in a subsequent period. In May 2014, the FASB issued accounting guidance outlining a single comprehensive five step model for entities to use in accounting for revenue arising from contracts with customers (ASC 606 Revenue from Contracts with Customers). The new guidance supersedes most current revenue recognition guidance, in an effort to converge the revenue recognition principles within U.S. GAAP. This new guidance also requires entities to disclose certain quantitative and qualitative information regarding the nature, amount, timing and uncertainty of qualifying revenue and cash flows arising from contracts with customers. Entities have the option of using a full retrospective or a modified retrospective approach to adopt the new guidance. Ashland has identified an implementation team that is currently evaluating the impact of the new standard on the Condensed Consolidated Financial Statements and the adoption method options available as well as the overall impact the new guidance will have on the organization. The assessment process consists of categorizing Ashland’s revenue streams and reviewing the current internal accounting policies and practices to determine potential differences that would result from applying the requirements of the new standard to revenue contracts. Additional discussions and meetings with each revenue stream team have occurred to solicit input, identify potential impacts and appropriate changes to Ashland’s business processes, systems and controls to support the revenue recognition and disclosure requirements under the new standard. Based on various preliminary assessments conducted to date, Ashland has identified agreements with distributors and customers that are subject to rebate and incentive programs that could contain elements of material rights and/or variable consideration. Ashland does not currently believe that these elements would result in a material change to how revenue would be recognized for these agreements. Ashland currently intends to adopt this standard using the modified retrospective approach and does not believe the impact will be material to the Condensed Consolidated Financial Statements but does expect there to be significant additional disclosures within the Notes to Condensed Consolidated Financial Statements. This guidance becomes effective for Ashland on October 1, 2018. In February 2018, the FASB issued guidance which permits entities to reclassify tax effects stranded in accumulated other comprehensive income (AOCI) as a result of U.S. tax reform legislation to retained earnings. Additionally, this guidance requires entities to disclose whether they made an election to reclassify the tax effects and to disclose their accounting policy for releasing income tax effects from AOCI. This guidance becomes effective for Ashland on October 1, 2019. Ashland is currently evaluating the impact this guidance may have on Ashland’s Condensed Consolidated Financial Statements. In March 2017, the FASB issued accounting guidance that will change how employers who sponsor defined benefit pension and/or postretirement benefit plans present the net periodic benefit cost in the Statement of Consolidated Comprehensive Income (Loss). This guidance requires employers to present the service cost component of net periodic benefit cost in the same caption within the Statement of Consolidated Comprehensive Income (Loss) as other employee compensation costs from services rendered during the period. All other components of the net periodic benefit cost will be presented separately outside of the operating income caption. This guidance must be applied retrospectively. Ashland elected to early adopt this guidance on October 1, 2017, which resulted in a reclassification of $3 million in income from the selling, general and administrative expense and cost of sales captions to the other net periodic benefit income caption in the Statement of Consolidated Comprehensive Income (Loss) for the six months ended March 31, 2017. The components of net periodic benefits income (costs) reclassified primarily relate to interest cost, expected return on assets, curtailments, settlements and actuarial gains and losses. Ashland did not have to adjust the classification of service cost since it previously was recorded within the caption required by the new guidance. See Note J for additional information on net periodic benefit costs. In March 2016, the FASB issued new accounting guidance for certain aspects of share-based payments to employees. This guidance requires all excess tax benefits and tax deficiencies related to share-based payments to be recognized as income tax expense in the Statements of Consolidated Comprehensive Income (Loss) instead of additional paid-in capital, and changes the classification of excess tax benefits from a financing activity to an operating activity within the Statements of Condensed Consolidated Cash Flows. This guidance also allows entities to make an accounting policy election to either estimate the number of awards that are expected to vest or account for forfeitures when they occur. In addition, this guidance increases the amount an employer can withhold to cover income taxes on awards and still qualify for equity classification and requires that cash paid by an employer when directly withholding shares for tax-withholding purposes be classified as a financing activity within the Statements of Condensed Consolidated Cash Flows. The guidance became effective for Ashland and was adopted on October 1, 2017. The guidance specifically related to the Statements of Consolidated Comprehensive Income (Loss) was adopted prospectively while the guidance related to the Statements of Condensed Consolidated Cash Flows was adopted retrospectively, as required by the guidance. Additionally, Ashland made a policy election to account for forfeitures when they occur across all share-based awards. Upon adoption, the overall impact on Ashland's Condensed Consolidated Financial Statements was not significant.
Fair Value of Financial Instruments Policy	As required by U.S. GAAP, Ashland uses applicable guidance for defining fair value, the initial recording and periodic remeasurement of certain assets and liabilities measured at fair value and related disclosures for instruments measured at fair value. Fair value accounting guidance establishes a fair value hierarchy, which prioritizes the inputs to valuation techniques used to measure fair value into three broad levels. The fair value hierarchy gives the highest priority to quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). An instrument’s categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the instrument’s fair value measurement. The three levels within the fair value hierarchy are described as follows. Level 1 – Observable inputs such as unadjusted quoted prices in active markets for identical assets or liabilities. Level 2 – Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. These include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active. Level 3 – Unobservable inputs for the asset or liability for which there is little, if any, market activity at the measurement date. Unobservable inputs reflect Ashland’s own assumptions about what market participants would use to price the asset or liability. The inputs are developed based on the best information available in the circumstances, which might include Ashland’s own financial data such as internally developed pricing models, discounted cash flow methodologies, as well as instruments for which the fair value determination requires significant management judgment. For assets that are measured using quoted prices in active markets (Level 1), the total fair value is the published market price per unit multiplied by the number of units held without consideration of transaction costs. Assets and liabilities that are measured using significant other observable inputs (Level 2) are primarily valued by reference to quoted prices of similar assets or liabilities in active markets, adjusted for any terms specific to that asset or liability. For all other assets and liabilities for which unobservable inputs are used (Level 3), fair value is derived using fair value models, such as a discounted cash flow model or other standard pricing models that Ashland deems reasonable.
Marketable Securities, Available-for-sale Securities, Policy	During 2015, Ashland diversified the restricted investments received from the January 2015 asbestos insurance settlement into primarily equity and corporate bond mutual funds that are designated as available-for-sale securities, classified as Level 1 measurements within the fair value hierarchy. Available-for-sale securities are reported at fair value with unrealized gains and losses, net of related deferred income taxes, included in the stockholders' equity section of the Condensed Consolidated Balance Sheets as a component of accumulated other comprehensive income (AOCI). Investment income and realized gains and losses on the available-for-sale securities are reported in the net interest and other financing expense caption in the Statements of Consolidated Comprehensive Income (Loss).
Marketable Securities, Trading Securities, Policy	Gains and losses related to deferred compensation investments are immediately recognized within the Statements of Consolidated Comprehensive Income (Loss).
Derivatives, Methods of Accounting, Derivatives Not Designated or Qualifying as Hedges, Policy	Ashland conducts business in a variety of foreign currencies. Accordingly, Ashland regularly uses foreign currency derivative instruments to manage exposure on certain transactions denominated in foreign currencies to curtail potential earnings volatility effects on certain assets and liabilities, including short-term inter-company loans, denominated in currencies other than Ashland’s functional currency of an entity. These derivative contracts generally require exchange of one foreign currency for another at a fixed rate at a future date and generally have maturities of less than twelve months. All contracts are valued at fair value with net changes in fair value recorded within the selling, general and administrative expense caption. The impacts of these contracts were largely offset by gains and losses resulting from the impact of changes in exchange rates on transactions denominated in non-functional currencies.
Inventories	Inventories are carried at the lower of cost or net realizable value. Inventories are primarily stated at cost using the weighted-average cost method. In addition, certain inventories are valued at cost using the last-in, first-out (LIFO) method.
Goodwill and Intangible Assets, Goodwill	Ashland reviews goodwill and indefinite-lived intangible assets for impairment annually or when events and circumstances indicate an impairment may have occurred. This annual assessment is performed as of July 1 and consists of Ashland determining each reporting unit’s current fair value compared to its current carrying value. For its July 1, 2017 assessment, Ashland determined that its reporting units for the allocation of goodwill are its three reportable segments: Specialty Ingredients, Composites and Intermediates and Solvents. At that time, Ashland determined no additional impairment existed.
Finite-Lived Intangible Asset	Intangible assets principally consist of trademarks and trade names, intellectual property and customer and supplier relationships. Intangible assets classified as finite are amortized on a straight-line basis over their estimated useful lives. The cost of trademarks and trade names is amortized principally over 3 to 25 years, intellectual property over 5 to 25 years, and customer and supplier relationships over 3 to 24 years.
Goodwill and Intangible Assets, Intangible Assets, Indefinite-Lived	Ashland annually reviews indefinite-lived intangible assets for possible impairment or whenever events or changes in circumstances indicate that carrying amounts may not be recoverable.
Commitments and Contingencies Policy	Ashland and Hercules have liabilities from claims alleging personal injury caused by exposure to asbestos. To assist in developing and annually updating independent reserve estimates for future asbestos claims and related costs given various assumptions, Ashland retained third party actuarial experts. Prior to 2018, Ashland retained Hamilton, Rabinovitz & Associates, Inc. (HR&A). During 2018, Ashland transitioned these responsibilities to Nathan Associates, Inc. (Nathan). The processes and methodologies used by Nathan are similar to the ones historically employed by HR&A. The methodology used by Nathan to project future asbestos costs is based largely on recent experience, including claim-filing and settlement rates, disease mix, enacted legislation, open claims and litigation defense. The claim experience of Ashland and Hercules are separately compared to the results of previously conducted third party epidemiological studies estimating the number of people likely to develop asbestos-related diseases. Those studies were undertaken in connection with national analyses of the population expected to have been exposed to asbestos. Using that information, Nathan estimates a range of the number of future claims that may be filed, as well as the related costs that may be incurred in resolving those claims. Changes in asbestos-related liabilities and receivables are recorded on an after-tax basis within the discontinued operations caption in the Statements of Consolidated Comprehensive Income (Loss).
Environmental Cost Policy	The total reserves for environmental remediation reflect Ashland’s estimates of the most likely costs that will be incurred over an extended period to remediate identified conditions for which the costs are reasonably estimable, without regard to any third-party recoveries. Engineering studies, probability techniques, historical experience and other factors are used to identify and evaluate remediation alternatives and their related costs in determining the estimated reserves for environmental remediation. Ashland continues to discount certain environmental sites and regularly adjusts its reserves as environmental remediation continues. Ashland has estimated the value of its probable insurance recoveries associated with its environmental reserve based on management’s interpretations and estimates surrounding the available or applicable insurance coverage.
Earnings Per Share	The following is the computation of basic and diluted earnings per share (EPS) from continuing operations attributable to Ashland. Stock appreciation rights (SARs), stock options and warrants available to purchase shares outstanding for each reporting period whose grant price was greater than the average market price of Ashland Common Stock for each applicable period were not included in the computation of income from continuing operations per diluted share because the effect of these instruments would be antidilutive. The total number of these shares outstanding was approximately 0.7 million and 0.1 million at March 31, 2018 and 2017, respectively. Earnings per share is reported under the treasury stock method.
Stock Incentive Plan Policy	Ashland has stock incentive plans under which key employees or directors are granted stock appreciation rights (SARs), performance awards or nonvested stock awards. Each program is typically a long-term incentive plan designed to link employee compensation with increased shareholder value or reward superior performance and encourage continued employment with Ashland. Ashland recognizes compensation expense for the grant date fair value of stock-based awards over the applicable vesting period.
Segment Reporting	Ashland determines its reportable segments based on how operations are managed internally for the products and services sold to customers, including how the results are reviewed by the chief operating decision maker, which includes determining resource allocation methodologies used for reportable segments. Operating income is the primary measure on the Statements of Consolidated Comprehensive Income (Loss) that is reviewed by the chief operating decision maker in assessing each reportable segment's financial performance. Ashland does not aggregate operating segments to arrive at these reportable segments.

Valvoline (Tables)

6 Months Ended

Mar. 31, 2018

Valvoline [Abstract]

Condensed Balance Sheet, Valvoline at Date of Distribution

The distribution was recorded at the carrying amount of Valvoline Inc.'s net assets which was a deficit of $187 million as of May 12, 2017, as follows:

	May 12
(In millions)	2017
ASSETS
Current assets
Cash and cash equivalents	$	179
Accounts receivable, net		385
Inventories		153
Other current assets		24
Total current assets		741
Noncurrent assets
Net property, plant and equipment		357
Goodwill		329
Equity and other unconsolidated investments		31
Deferred income taxes		391
Other noncurrent assets		93
Total noncurrent assets		1,201
Total assets		1,942
LIABILITIES AND EQUITY
Current liabilities
Short-term debt		75
Current portion of long-term debt		16
Trade and other payables		353
Other current liabilities		34
Total current liabilities		478
Noncurrent liabilities
Long-term debt		662
Employee benefit obligations		826
Other long-term liabilities		163
Total noncurrent liabilities		1,651
Total liabilities		2,129
Net deficit	$	(187	)

Acquisitions (Tables)

6 Months Ended

Mar. 31, 2018

Business Combinations [Abstract]

Business Combination, Separately Recognized Transactions

The following table summarizes the current preliminary values of the assets acquired and liabilities assumed at the date of acquisition.

	At
	May 17, 2017
Preliminary purchase price allocation (in millions)	As Adjusted
Assets:
Accounts receivable	$	52
Inventory		74
Other current assets		4
Intangible assets		330
Goodwill		288
Property, plant and equipment		97
Other noncurrent assets		20
Liabilities:
Accounts payable		(33	)
Deferred tax - net		(138	)
Other noncurrent liabilities		(14	)
Total purchase price	$	680

Schedule of Finite-Lived Intangible Assets as Part of Business Combination

The following details the total intangible assets identified as of May 17, 2017.

Discontinued Operations (Tables)

6 Months Ended

Mar. 31, 2018

Discontinued Operations And Disposal Groups [Abstract]

Schedule of Disposal Groups Including Discontinued Operations, Income Statement and Balance Sheet Additional Disclosures

	Three months ended				Six months ended
	March 31				March 31
(In millions)	2018		2017		2018		2017
Income from discontinued operations (net of tax)
Valvoline	$	4	$	73	$	7	$	149
Asbestos-related litigation		3		—		3		—
Water Technologies		—		3		—		3
Total income from discontinued operations (net of tax)	$	7	$	76	$	10	$	152

	Three			Six
	months ended			months ended
(In millions)	March 31, 2017			March 31, 2017
Income (loss) from discontinued operations attributable to Valvoline
Sales	$	514		$	1,003
Cost of sales		(310	)		(603	)
Selling, general and administrative expense		(90	)		(172	)
Research and development expense		(3	)		(6	)
Equity and other income		6			15
Pretax operating income of discontinued operations		117			237
Net interest and other financing expense		(9	)		(18	)
Pretax income of discontinued operations		108			219
Income tax expense		(35	)		(70	)
Income from discontinued operations	$	73		$	149

Summary of Financial Instruments Subject to Recurring Fair Value Measurements

Tabular disclosure of information related to a disposal group. Includes, but is not limited to, a discontinued operation, disposal classified as held-for-sale or disposed of by means other than sale or disposal of an individually significant component.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
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-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=65878427&loc=SL51721533-107759

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
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-Section 50
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
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Reference 5: http://www.xbrl.org/2003/role/presentationRef
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Reference 6: http://www.xbrl.org/2003/role/presentationRef
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Reference 7: http://www.xbrl.org/2003/role/presentationRef
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-Topic 205
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-Section 50
-Paragraph 5C
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721675-107760

Reference 8: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
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-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84176398&loc=d3e2941-110230

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5B
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721673-107760

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 3A
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721659-107760

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
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Reference 13: http://www.xbrl.org/2003/role/presentationRef
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-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721677-107760

+ Details

Fair Value Measurements (Tables)

6 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

The following table summarizes financial instruments subject to recurring fair value measurements as of March 31, 2018.

	Carrying		Total fair		Quoted prices in active markets for identical assets		Significant other observable inputs		Significant unobservable inputs
(In millions)	value		value		Level 1		Level 2		Level 3
Assets
Cash and cash equivalents	$	225	$	225	$	225	$	—	$	—
Restricted investments (a)		333		333		333		—		—
Deferred compensation investments (b)		160		160		—		160		—
Investment of captive insurance company		4		4		4		—		—
Foreign currency derivatives		4		4		—		4		—
Total assets at fair value	$	726	$	726	$	562	$	164	$	—
Liabilities
Foreign currency derivatives	$	21	$	21	$	—	$	21	$	—

(a)

Included in restricted investments is $30 million classified in the other current assets caption on the Condensed Consolidated Balance Sheets.

(b)

Included in other noncurrent assets in the Condensed Consolidated Balance Sheets.

The following table summarizes financial asset instruments subject to recurring fair value measurements as of September 30, 2017.

	Carrying		Total fair		Quoted prices in active markets for identical assets		Significant other observable inputs		Significant unobservable inputs
(In millions)	value		value		Level 1		Level 2		Level 3
Assets
Cash and cash equivalents	$	566	$	566	$	566	$	—	$	—
Restricted investments (a)		332		332		332		—		—
Deferred compensation investments (b)		158		158		—		158		—
Investment of captive insurance company		3		3		3		—		—
Foreign currency derivatives		2		2		—		2		—
Total assets at fair value	$	1,061	$	1,061	$	901	$	160	$	—
Liabilities
Foreign currency derivatives	$	36	$	36	$	—	$	36	$	—

(a)

Included in restricted investments is $30 million classified in the other current assets caption on the Condensed Consolidated Balance Sheets.

(b)

Included in other noncurrent assets in the Condensed Consolidated Balance Sheets.

Summary of Available-for-sale Securities Portfolio

The following table provides a summary of the available-for-sale securities portfolio as of March 31, 2018 and September 30, 2017:

(In millions)	March 31 2018			September 30 2017
Original cost	$	335		$	335
Accumulated adjustments, net		(38	)		(24	)
Adjusted cost, beginning of year (a)		297			311
Investment income (b)		4			9
Net unrealized gain		37			35
Realized gains		4			2
Settlement funds		8			2
Disbursements		(17	)		(27	)
Fair value	$	333		$	332

(a)

The accumulated adjustments include investment income, realized gains, disbursements and settlements recorded in previous periods.

(b)

Investment income for the demand deposit includes interest income as well as dividend income transferred from the equity and corporate bond mutual funds.

The following table presents gross unrealized gains and losses for the restricted investment available-for-sale securities as of March 31, 2018 and September 30, 2017:

			Gross		Gross
(In millions)	Adjusted Cost		Unrealized Gain		Unrealized Loss			Fair Value
As of March 31, 2018
Demand deposit	$	22	$	—	$	—		$	22
Equity mutual fund		154		40		—			194
Corporate bond mutual fund		120		—		(3	)		117
Fair value	$	296	$	40	$	(3	)	$	333

As of September 30, 2017
Demand deposit	$	9	$	—	$	—		$	9
Equity mutual fund		168		34		—			202
Corporate bond mutual fund		120		1		—			121
Fair value	$	297	$	35	$	—		$	332

Summary of Investment Income, Realized Gains and Disbursements Related to Investments

The following table presents the investment income, realized gains and disbursements related to the investments within the portfolio for the three and six months ended March 31, 2018 and 2017.

	Three months ended						Six months ended
	March 31						March 31
(In millions)	2018			2017			2018			2017
Investment income	$	2		$	2		$	4		$	5
Realized gains		3			2			4			2
Disbursements		(12	)		(12	)		(17	)		(12	)

Summary of Net Gains and Losses on Foreign Currency Derivatives

The following table summarizes the net gains and losses recognized during the three and six months ended March 31, 2018 and 2017 within the Statements of Consolidated Comprehensive Income (Loss).

	Three months ended					Six months ended
	March 31					March 31
(In millions)	2018			2017		2018			2017
Foreign currency derivative gains (losses)	$	(16	)	$	8	$	(27	)	$	—

Summary of Fair Values of Outstanding Foreign Currency Derivatives

	March 31		September 30
(In millions)	2018		2017
Foreign currency derivative assets	$	4	$	2
Notional contract values		302		79

Foreign currency derivative liabilities	$	21	$	36
Notional contract values		958		1,601

Tabular disclosure of available-for-sale securities which includes, but is not limited to, changes in the cost basis and fair value, fair value and gross unrealized gain (loss), fair values by type of security, contractual maturity and classification, amortized cost basis, contracts to acquire securities to be accounted for as available-for-sale, debt maturities, transfers to trading, change in net unrealized holding gain (loss) net of tax, continuous unrealized loss position fair value, aggregate losses qualitative disclosures, other than temporary impairment (OTTI) losses or other disclosures related to available for sale securities.

Goodwill And Intangible Assets Disclosure [Abstract]

Inventories (Tables)

6 Months Ended

Mar. 31, 2018

Inventory Disclosure [Abstract]

Summary of Inventories

The following table summarizes Ashland’s inventories as of the reported Condensed Consolidated Balance Sheet dates.

(In millions)	March 31, 2018			September 30, 2017
Finished products	$	404		$	390
Raw materials, supplies and work in process		248			245
LIFO carrying values		(3	)		(1	)
	$	649		$	634

Goodwill and Other Intangibles (Tables)

6 Months Ended

Mar. 31, 2018

Summary of Goodwill by Reportable Segment

The following is a progression of goodwill by reportable segment for the six months ended March 31, 2018.

	Specialty				Intermediates
(In millions)	Ingredients		Composites		and Solvents		(a)	Total
Balance at September 30, 2017	$	2,315	$	150	$	—		$	2,465
Acquisitions (b)		4		—		—			4
Currency translation		33		1		—			34
Balance at March 31, 2018	$	2,352	$	151	$	—		$	2,503

(a)

As of March 31, 2018, there was accumulated impairment of $171 million related to the Intermediates and Solvents reportable segment.

(b)

Relates to the acquisition of Vornia Limited during the six months ended March 31, 2018. See Note C for more information.

Summary of Intangible Assets

Intangible assets were comprised of the following as of March 31, 2018 and September 30, 2017.

	March 31, 2018
	Gross					Net
	carrying		Accumulated			carrying
(In millions)	amount		amortization			amount
Definite-lived intangibles
Trademarks and trade names	$	67	$	(23	)	$	44
Intellectual property		773		(354	)		419
Customer and supplier relationships		786		(260	)		526

Total definite-lived intangibles		1,626		(637	)		989
Indefinite-lived intangibles
Trademarks and trade names		301		—			301
Total intangible assets	$	1,927	$	(637	)	$	1,290

	September 30, 2017
	Gross					Net
	carrying		Accumulated			carrying
(In millions)	amount		amortization			amount
Definite-lived intangibles
Trademarks and trade names	$	67	$	(22	)	$	45
Intellectual property		757		(326	)		431
Customer and supplier relationships		777		(235	)		542
Total definite-lived intangibles		1,601		(583	)		1,018

Indefinite-lived intangibles
Trademarks and trade names		301		—			301
Total intangible assets	$	1,902	$	(583	)	$	1,319

Debt (Tables)

6 Months Ended

Mar. 31, 2018

Debt Disclosure [Abstract]

Summary of Current and Long-term Debt

The following table summarizes Ashland’s current and long-term debt as of the dates reported in the Condensed Consolidated Balance Sheets.

(In millions)	March 31, 2018			September 30, 2017
4.750% notes, due 2022	$	1,082		$	1,082
Term Loan B, due 2024		596			599
6.875% notes, due 2043		376			376
Revolving Credit Facility		—			173
Term Loan A, due 2022		250			250
Term Loan A, due 2020		250			250
Accounts receivable securitization		48			56
6.50% junior subordinated notes, due 2029		51			51
Medium-term notes, due 2019, interest of 9.4%		5			5
Other (a)		(20	)		(23	)
Total debt		2,638			2,819
Short-term debt (includes current portion of long-term debt)		(59	)		(235	)
Long-term debt (less current portion)	$	2,579		$	2,584

(a)

Other includes $23 million and $25 million of debt issuance cost discounts as of March 31, 2018 and September 30, 2017, respectively.

Income Taxes (Tables)

6 Months Ended

Mar. 31, 2018

Income Tax Disclosure [Abstract]

Summary of Changes in Unrecognized Tax Benefits

Changes in unrecognized tax benefits are summarized as follows for the six months ended March 31, 2018.

(In millions)
Balance at October 1, 2017	$	194
Increases related to positions taken on items from prior years		3
Decreases related to positions taken on items from prior years		(1	)
Increases related to positions taken in the current year		6
Lapse of statute of limitations		(1	)
Balance at March 31, 2018	$	201

Employee Benefit Plans (Tables)

6 Months Ended

Mar. 31, 2018

Compensation And Retirement Disclosure [Abstract]

Schedule of Components of Pension and Other Postretirement Benefit Costs for Continuing Operation

The following table details the components of pension and other postretirement benefit costs for continuing operations.

	Pension benefits						Other postretirement benefits
(In millions)	2018			2017			2018		2017
Three months ended March 31
Service cost (a)	$	2		$	2		$	—	$	—
Interest cost (b)		2			2			—		—
Expected return on plan assets (b)		(3	)		(2	)		—		—
Total net periodic benefit costs	$	1		$	2		$	—	$	—
Six months ended March 31
Service cost (a)	$	4		$	4		$	1	$	—
Interest cost (b)		5			4			—		1
Expected return on plan assets (b)		(6	)		(6	)		—		—
Actuarial gain (b)		—			—			—		(2	)
Total net periodic benefit costs (income)	$	3		$	2		$	1	$	(1	)

(a)

(b)

Litigation, Claims and Contingencies (Tables)

6 Months Ended

Mar. 31, 2018

Loss Contingencies [Line Items]

Reconciliation of Changes in the Environmental Contingencies and Asset Retirement Obligations Reserve

The following table provides a reconciliation of the changes in the environmental remediation reserves during the six months ended March 31, 2018 and 2017.

	Six months ended
	March 31
(In millions)	2018			2017
Reserve - beginning of period	$	163		$	177
Disbursements		(16	)		(15	)
Revised obligation estimates and accretion		17			5
Reserve - end of period	$	164		$	167

Components of Environmental Remediation Expense

	Three months ended					Six months ended
	March 31					March 31
(In millions)	2018			2017		2018			2017
Environmental expense	$	4		$	1	$	16		$	5
Accretion		—			—		1			—
Legal expense		2			4		3			5
Total expense		6			5		20			10

Insurance receivable (a)		(1	)		—		(1	)		—
Total expense, net of receivable activity (b)	$	5		$	5	$	19		$	10

(a)

Activity of $0 denotes value less than $1 million.

(b)

Summary of Asbestos Claims Activity

Loss Contingencies [Line Items]

A summary of Ashland asbestos claims activity, excluding Hercules claims, follows.

	Six months ended
	March 31						Years ended September 30
(In thousands)	2018			2017			2017			2016			2015
Open claims - beginning of year		54			57			57			60			65
New claims filed		1			1			2			2			2
Claims settled		—			—			(1	)		—			—
Claims dismissed		(2	)		(2	)		(4	)		(5	)		(7	)
Open claims - end of period		53			56			54			57			60

Progression of Activity in the Asbestos Reserve Accounts

A progression of activity in the asbestos reserve is presented in the following table.

	Six months ended
	March 31						Years ended September 30
(In millions)	2018			2017			2017			2016			2015
Asbestos reserve - beginning of year	$	419		$	415		$	415		$	409		$	438
Reserve adjustment		—			—			36			37			—
Amounts paid		(17	)		(18	)		(32	)		(31	)		(29	)
Asbestos reserve - end of period (a)	$	402		$	397		$	419		$	415		$	409

(a)

Included $34 million classified in accrued expenses and other liabilities on the Condensed Consolidated Balance Sheets as of March 31, 2018 and September 30, 2017.

Progression of Insurance Receivable

A progression of activity in the Ashland insurance receivable is presented in the following table.

	Six months ended
	March 31						Years ended September 30
(In millions)	2018			2017			2017			2016			2015
Insurance receivable - beginning of year	$	155		$	151		$	151		$	150		$	402
Receivable adjustment		—			—			15			16			(3	)
Insurance settlement		—			(5	)		(5	)		(4	)		(227	)
Amounts collected		(6	)		(2	)		(6	)		(11	)		(22	)
Insurance receivable - end of period (a)	$	149		$	144		$	155		$	151		$	150

(a)

Included $14 million classified in accounts receivable on the Condensed Consolidated Balance Sheets as of March 31, 2018 and September 30, 2017.

Summary of Asbestos Claims Activity

Loss Contingencies [Line Items]

A summary of Hercules’ asbestos claims activity follows.

	Six months ended
	March 31						Years ended September 30
(In thousands)	2018			2017			2017			2016			2015
Open claims - beginning of year		12			15			15			20			21
New claims filed		1			1			1			1			1
Claims dismissed		(1	)		(3	)		(4	)		(6	)		(2	)
Open claims - end of period		12			13			12			15			20

Progression of Activity in the Asbestos Reserve Accounts

A progression of activity in the asbestos reserve is presented in the following table.

	Six months ended
	March 31						Years ended September 30
(In millions)	2018			2017			2017			2016			2015
Asbestos reserve - beginning of year	$	323		$	321		$	321		$	311		$	329
Reserve adjustments		—			—			16			25			4
Amounts paid		(12	)		(5	)		(14	)		(15	)		(22	)
Asbestos reserve - end of period (a)	$	311		$	316		$	323		$	321		$	311

(a)

Included $14 million classified in accrued expenses and other liabilities on the Condensed Consolidated Balance Sheets as of March 31, 2018 and September 30, 2017.

Progression of Insurance Receivable

A progression of activity in the Hercules insurance receivable is presented in the following table.

	Six months ended
	March 31				Years ended September 30
(In millions)	2018		2017		2017		2016		2015
Insurance receivable - beginning of year	$	68	$	63	$	63	$	56	$	77
Receivable adjustment		—		—		5		7		1
Insurance settlement		—		—		—		—		(22	)
Insurance receivable - end of period	$	68	$	63	$	68	$	63	$	56

Earnings Per Share (Tables)

6 Months Ended

Mar. 31, 2018

Earnings Per Share [Abstract]

Computation of Basic and Diluted Earnings per Share

	Three months ended				Six months ended
	March 31				March 31
(In millions, except per share data)	2018		2017		2018		2017
Numerator
Numerator for basic and diluted EPS -
Income (loss) from continuing operations	$	66	$	29	$	59	$	(37	)
Denominator
Denominator for basic EPS - Weighted-average
common shares outstanding		63		62		63		62
Share based awards convertible to common shares (a)		1		1		1		—
Denominator for diluted EPS - Adjusted weighted-
average shares and assumed conversions		64		63		64		62

EPS from continuing operations
Basic	$	1.06	$	0.46	$	0.94	$	(0.59	)
Diluted		1.04		0.46		0.93		(0.59	)

(a)

Equity Items (Tables)

6 Months Ended

Mar. 31, 2018

Components of Accumulated Other Comprehensive Income (Loss)

Components of other comprehensive income (loss) recorded in the Statements of Consolidated Comprehensive Income (Loss) are presented below, before tax and net of tax effects.

	2018									2017
(In millions)	Before tax			Tax (expense) benefit			Net of tax			Before tax			Tax (expense) benefit			Net of tax
Three months ended March 31
Other comprehensive income (loss)
Unrealized translation gain	$	55		$	—		$	55		$	58		$	2		$	60
Amortization of unrecognized prior
service credit (a)		—			—			—			(3	)		1			(2	)
Net change in available-for-sale securities:
Unrealized loss		(5	)		1			(4	)		9			(2	)		7
Reclassification adjustment for gains
included in net income		(3	)		1			(2	)		(2	)		1			(1	)
Total other comprehensive income	$	47		$	2		$	49		$	62		$	2		$	64

Six months ended March 31
Other comprehensive income (loss)
Unrealized translation gain (loss)	$	58		$	—		$	58		$	(92	)	$	6		$	(86	)
Amortization of unrecognized prior
service credit (a)		—			—			—			(6	)		2			(4	)
Net change in available-for-sale securities:
Unrealized gain		6			(1	)		5			9			(2	)		7
Reclassification adjustment for gains
included in net income		(4	)		1			(3	)		(2	)		1			(1	)
Total other comprehensive income (loss)	$	60		$	—		$	60		$	(91	)	$	7		$	(84	)

(a)

Stock Incentive Plans (Tables)

6 Months Ended

Mar. 31, 2018

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Components of Stock-Based Compensation Expense Included in Continuing Operations

The components of Ashland’s pretax stock-based compensation expense included in continuing operations are as follows:

	Three months ended				Six months ended
	March 31				March 31
(In millions)	2018 (a)		2017 (b)		2018 (a)		2017 (b)
SARs	$	2	$	2	$	3	$	3
Nonvested stock awards		5		3		11		7
Performance share awards		2		2		6		4
	$	9	$	7	$	20	$	14

(a)

(b)

Reportable Segment Information (Tables)

6 Months Ended

Mar. 31, 2018

Segment Reporting [Abstract]

Summary of Financial Information for Each Reportable Segment

The following table presents various financial information for each reportable segment for the three and six months ended March 31, 2018 and 2017.

	Three months ended						Six months ended
	March 31						March 31
(In millions - unaudited)	2018			2017			2018			2017
SALES
Specialty Ingredients	$	646		$	544		$	1,196		$	1,026
Composites		238			186			456			351
Intermediates and Solvents		90			76			164			133
	$	974		$	806		$	1,816		$	1,510
OPERATING INCOME (LOSS)
Specialty Ingredients	$	89		$	74		$	131		$	114
Composites		19			13			36			29
Intermediates and Solvents		4			(3	)		13			(11	)
Unallocated and other		(17	)		(31	)		(47	)		(64	)
	$	95		$	53		$	133		$	68

Significant Accounting Policies - Additional Information (Details) shares in Millions, $ in Millions	6 Months Ended		7 Months Ended
	Mar. 31, 2018 ReportableSegment	Mar. 31, 2017 USD ($)	May 12, 2017 shares
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Valvoline Shares Owned by Ashland \| shares			170
Sale of Stock, Percentage of Ownership after Transaction			83.00%
Number of reportable segments \| ReportableSegment	3
Expenses reclassified to other net periodic benefit income \| $		$ 3

Valvoline - Additional Information (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended		7 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017	May 12, 2017	Sep. 30, 2016
Distribution of Valvoline [Line Items]
Valvoline Shares Owned by Ashland					170
Sale of Stock, Percentage of Ownership after Transaction					83.00%
Stockholders' Equity Note, Stock Split, Conversion Ratio					2.745338
Net assets deficit					$ (187)
Discontinued Operations [Member]
Distribution of Valvoline [Line Items]
Separation costs		$ 7		$ 12
Selling, General and Administrative Expense [Member]
Distribution of Valvoline [Line Items]
Separation costs	$ 2	$ 26	$ 8	$ 54
Valvoline Inc. [Member]
Distribution of Valvoline [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners						17.00%

Valvoline - Condensed Balance Sheet, Valvoline at Date of Distribution (Details) - USD ($)
$ in Millions

Mar. 31, 2018

Sep. 30, 2017

May 17, 2017

May 12, 2017

Current assets

Accounts receivable, net

^[1]

$ 717

$ 612

Inventories

649

634

Other current assets

122

Total current assets

1,713

1,903

Noncurrent assets

Net property, plant and equipment

1,940

1,970

Goodwill

2,503

2,465

$ 288

Deferred income taxes

Other noncurrent assets

461

422

Total noncurrent assets

6,728

6,715

Total assets

8,441

8,618

Current liabilities

Short-term debt

235

Trade and other payables

387

409

Other current liabilities

266

324

Total current liabilities

712

968

Noncurrent liabilities

Long-term debt

2,579

2,584

Employee benefit obligations

190

191

Other long-term liabilities

541

400

Total noncurrent liabilities

$ 4,218

$ 4,244

Net deficit

$ (187)

Valvoline [Member]

Current assets

Net property, plant and equipment

179

Accounts receivable, net

385

Inventories

153

Other current assets

Total current assets

741

Noncurrent assets

357

Goodwill

329

Equity and other unconsolidated investments

Deferred income taxes

391

Other noncurrent assets

Total noncurrent assets

1,201

Total assets

1,942

Current liabilities

Short-term debt

Current portion of long-term debt

Trade and other payables

353

Other current liabilities

Total current liabilities

478

Noncurrent liabilities

Long-term debt

662

Employee benefit obligations

826

Other long-term liabilities

163

Total noncurrent liabilities

1,651

Total liabilities

2,129

Net deficit

$ (187)

[1]	Accounts receivable includes an allowance for doubtful accounts of $9 million at both March 31, 2018 and September 30, 2017.

Acquisitions - Additional Information (Details) $ in Millions		1 Months Ended	6 Months Ended	12 Months Ended
	May 17, 2017 USD ($) Facility	Jan. 31, 2018 USD ($)	Mar. 31, 2018 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Business Acquisition, Revenue Reported by Acquired Entity for Last Annual Period				$ 300
Number of manufacturing facilities \| Facility	14
Business acquisition, purchase price	$ 680
Working capital adjustments	20
Goodwill, Purchase Accounting Adjustments			$ 1
Accounts payable, purchase accounting adjustments			1
Intangible assets	330
Goodwill	$ 288		$ 2,503		$ 2,465
Vornia Limited [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Business combination, consideration transferred		$ 12
Business acquisition future payment		1
Goodwill		4
intellectual property		$ 8

Acquisitions - Summary of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Millions	Mar. 31, 2018	Sep. 30, 2017	May 17, 2017
Business Combinations [Abstract]
Accounts receivable			$ 52
Inventory			74
Other current assets			4
Intangible assets			330
Goodwill	$ 2,503	$ 2,465	288
Property, plant and equipment			97
Other noncurrent assets			20
Accounts payable			(33)
Deferred tax - net			(138)
Other noncurrent liabilities			(14)
Total purchase price			$ 680

Acquisitions - Summary of Total Intangible Assets Identified (Details) $ in Millions	May 17, 2017 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total intangible assets	$ 330
Trademarks and Trade Names [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total intangible assets	$ 26
Weighted-average amortization period	15 years
Intellectual Property [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total intangible assets	$ 68
Weighted-average amortization period	22 years
Customer and supplier relationships [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total intangible assets	$ 236
Weighted-average amortization period	20 years

Discontinued Operations - Additional Information (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended		7 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017	May 12, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Valvoline Shares Owned by Ashland					170
Income from discontinued operations (net of tax)	$ 7	$ 76	$ 10	$ 152
Asbestos [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income from discontinued operations (net of tax)	$ 3		$ 3

Amount after tax of income (loss) from a discontinued operation including the portion attributable to the noncontrolling interest. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.

Discontinued Operations - Components of Consolidated Comprehensive Income (Loss) Related to Discontinued Operations (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Income from discontinued operations (net of tax)
Total income from discontinued operations (net of tax)	$ 7	$ 76	$ 10	$ 152
Valvoline [Member]
Income from discontinued operations (net of tax)
Total income from discontinued operations (net of tax)	4	73	7	149
Asbestos [Member]
Income from discontinued operations (net of tax)
Total income from discontinued operations (net of tax)	$ 3		$ 3
Water Technologies [Member]
Income from discontinued operations (net of tax)
Total income from discontinued operations (net of tax)		$ 3		$ 3

Carrying (Reported) Amount, Fair Value Disclosure [Member]

Discontinued Operations - Reconciliation of Consolidated Income (Loss) From Discontinued Operations (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Income (loss) from discontinued operations attributable to Valvoline
Research and development expense	$ (21)	$ (21)	$ (43)	$ (41)
Income tax expense	(1)	5	(15)	45
Income from discontinued operations	7	76	10	152
Valvoline [Member]
Income (loss) from discontinued operations attributable to Valvoline
Sales		514		1,003
Cost of sales		(310)		(603)
Selling, general and administrative expense		(90)		(172)
Research and development expense		(3)		(6)
Equity and other income		6		15
Pretax operating income of discontinued operations		117		237
Net interest and other financing expense		(9)		(18)
Pretax income of discontinued operations		108		219
Income tax expense		(35)		(70)
Income from discontinued operations	$ 4	$ 73	$ 7	$ 149

Fair Value Measurements - Summary of Financial Instruments Subject to Recurring Fair Value Measurements (Details) - Fair Value, Measurements, Recurring [Member] - USD ($)
$ in Millions

Mar. 31, 2018

Sep. 30, 2017

ASSETS

$ 225

$ 566

^[1]

333

332

^[2]

160

158

726

1,061

Estimate of Fair Value, Fair Value Disclosure [Member]

ASSETS

225

566

^[1]

333

332

^[2]

160

158

726

1,061

Fair Value, Inputs, Level 1 [Member]

ASSETS

225

566

^[1]

333

332

^[2]

562

901

Fair Value, Inputs, Level 2 [Member]

ASSETS

^[1]

^[2]

160

158

164

160

Fair Value, Inputs, Level 3 [Member]

ASSETS

^[1]

^[2]

Schedule of Available-for-sale Securities [Line Items]

$ 0

[1]	Included in restricted investments is $30 million classified in the other current assets caption on the Condensed Consolidated Balance Sheets.
[2]	Included in other noncurrent assets in the Condensed Consolidated Balance Sheets.

Fair Value Measurements - Summary of Financial Instruments Subject to Recurring Fair Value Measurements (Parenthetical) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Restricted Investments, Current	$ 30	$ 30

Fair Value Measurements - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017	Sep. 30, 2015	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Litigation Settlement, Amount					$ 398,000,000
Increase (Decrease) in Restricted Cash					$ 335,000,000
Restricted Investments, Current	$ 30,000,000		$ 30,000,000			$ 30,000,000
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities	0	$ 0	0	$ 0
Other financial instruments [Abstract]
Long-term Debt, Carrying Value	2,613,000,000		2,613,000,000			2,615,000,000
Long-term Debt, Fair Value	$ 2,710,000,000		$ 2,710,000,000			$ 2,768,000,000

Fair Value Measurements - Summary of Available-for-sale Securities Portfolio (Details) - USD ($)
$ in Millions

3 Months Ended

6 Months Ended

12 Months Ended

Mar. 31, 2018

Mar. 31, 2017

Mar. 31, 2018

Mar. 31, 2017

Sep. 30, 2017

Original cost

$ 335

Accumulated adjustments, net

(38)

(24)

Available-for-sale Securities [Member]

^[1]

297

311

Investment income

$ 2

^[2]

$ 5

^[2]

(12)

$ (12)

(17)

$ (12)

(27)

Fair value

333

332

Schedule of Available-for-sale Securities [Line Items]

Corporate bond mutual fund [Member]

296

297

Fair value

333

332

Unrealized gain

Unrealized loss

(3)

Schedule of Available-for-sale Securities [Line Items]

Corporate bond mutual fund, unrealized gain

120

Corporate bond mutual fund, unrealized loss

(3)

Corporate bond mutual fund, Fair value

117

121

Equity mutual fund [Member]

Schedule of Available-for-sale Securities [Line Items]

Equity mutual fund, unrealized gain

154

168

Equity mutual fund, unrealized loss

Equity mutual fund, Fair value

194

202

Demand Deposits [Member]

Schedule of Available-for-sale Securities [Line Items]

Demand deposit

$ 22

$ 9

[1]	The accumulated adjustments include investment income, realized gains, disbursements and settlements recorded in previous periods.
[2]	Investment income for the demand deposit includes interest income as well as dividend income transferred from the equity and corporate bond mutual funds.

Fair Value Measurements - Summary of Investment Income, Realized Gains and Disbursements Related to Investments (Details) - USD ($)
$ in Millions

3 Months Ended

6 Months Ended

12 Months Ended

Mar. 31, 2018

Mar. 31, 2017

Mar. 31, 2018

Mar. 31, 2017

Sep. 30, 2017

Fair Value Disclosures [Abstract]

Investment income

$ 2

$ 4

^[1]

$ 5

$ 9

^[1]

Realized gains

Disbursements

$ (12)

$ (17)

$ (12)

$ (27)

[1]	Investment income for the demand deposit includes interest income as well as dividend income transferred from the equity and corporate bond mutual funds.

Fair Value Measurements - Summary of Net Gains and Losses on Foreign Currency Derivatives (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Foreign Exchange Contract [Member] \| Not Designated as Hedging Instrument [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency derivative gains (losses)	$ (16)	$ 8	$ (27)	$ 0

Fair Value Measurements - Summary of Fair Values of Outstanding Foreign Currency Derivatives (Details) - Foreign Exchange Contract [Member] - USD ($) $ in Millions	Mar. 31, 2018	Sep. 30, 2017
Accounts Receivable [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency derivative assets	$ 4	$ 2
Notional contract values	302	79
Accrued Expenses and Other Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional contract values	958	1,601
Foreign currency derivative liabilities	$ 21	$ 36

Inventories - Summary of Inventories (Details) - USD ($) $ in Millions	Mar. 31, 2018	Sep. 30, 2017
Inventory Disclosure [Abstract]
Finished products	$ 404	$ 390
Raw materials, supplies and work in process	248	245
LIFO carrying values	(3)	(1)
Inventory, Net	$ 649	$ 634

Goodwill and Other Intangibles - Additional Information (Details) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)	Mar. 31, 2018 USD ($) ReportableSegment	Mar. 31, 2017 USD ($)
Finite Lived Intangible Assets [Line Items]
Number of reportable segments \| ReportableSegment			3
Finite-Lived Intangible Assets, Net [Abstract]
Amortization expense recognized on intangible assets	$ 24	$ 19	$ 48	$ 38
Expected future amortization expense [Abstract]
2018 (includes six months actual and six months estimated)	95		95
2019	91		91
2020	90		90
2021	90		90
2022	$ 88		$ 88
Minimum [Member] \| Trademarks and Trade Names [Member]
Intangible Assets, Net [Abstract]
Useful life (in years)			3 years
Minimum [Member] \| Intellectual Property [Member]
Intangible Assets, Net [Abstract]
Useful life (in years)			5 years
Minimum [Member] \| Customer and supplier relationships [Member]
Intangible Assets, Net [Abstract]
Useful life (in years)			3 years
Maximum [Member] \| Trademarks and Trade Names [Member]
Intangible Assets, Net [Abstract]
Useful life (in years)			25 years
Maximum [Member] \| Intellectual Property [Member]
Intangible Assets, Net [Abstract]
Useful life (in years)			25 years
Maximum [Member] \| Customer and supplier relationships [Member]
Intangible Assets, Net [Abstract]
Useful life (in years)			24 years

Goodwill and Other Intangibles - Summary of Goodwill by Reportable Segment (Details)
$ in Millions

6 Months Ended

Mar. 31, 2018

USD ($)

$ 2,465

^[1]

Specialty Ingredients [Member]

2,503

2,315

^[1]

2,352

Composites [Member]

150

^[1]

Intermediates and Solvents [Member]

151

^[2]

^[1],[2]

^[2]

$ 0

^[2]

[1]	Relates to the acquisition of Vornia Limited during the six months ended March 31, 2018. See Note C for more information.
[2]	As of March 31, 2018, there was accumulated impairment of $171 million related to the Intermediates and Solvents reportable segment.

Goodwill and Other Intangibles - Summary of Intangible Assets (Details) - USD ($) $ in Millions	Mar. 31, 2018	Sep. 30, 2017
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	$ 1,626	$ 1,601
Accumulated amortization	(637)	(583)
Net carrying amount	989	1,018
Indefinite-Lived Intangible Assets (Excluding Goodwill) [Abstract]
Intangible Assets, Gross (Excluding Goodwill)	1,927	1,902
Intangibles	1,290	1,319
Trademarks and Trade Names [Member]
Indefinite-Lived Intangible Assets (Excluding Goodwill) [Abstract]
Trademarks and trade names	301	301
Trademarks and Trade Names [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	67	67
Accumulated amortization	(23)	(22)
Net carrying amount	44	45
Intellectual Property [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	773	757
Accumulated amortization	(354)	(326)
Net carrying amount	419	431
Customer and supplier relationships [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	786	777
Accumulated amortization	(260)	(235)
Net carrying amount	$ 526	$ 542

Debt - Summary of Current and Long-term Debt (Details) - USD ($)
$ in Millions

Mar. 31, 2018

Sep. 30, 2017

Short-term debt (includes current portion of long-term debt)

$ 2,613

$ 2,615

Other

^[1]

(20)

(23)

Total debt

2,638

2,819

(59)

(235)

Long-term debt (less current portion)

2,579

2,584

Notes due 2022 [Member]

Term Loan B due 2024 [Member]

1,082

596

599

Notes due 2043 [Member]

2017 Revolving Credit Facility [Member]

376

Term Loan A due 2022 [Member]

173

Term Loan A due 2020 [Member]

250

Accounts Receivable Securitization [Member]

250

Junior Subordinated Debt [Member]

Medium-term Notes [Member]

Defined Benefit Plan Disclosure [Line Items]

$ 5

[1]	Other includes $23 million and $25 million of debt issuance cost discounts as of March 31, 2018 and September 30, 2017, respectively.

Debt - Summary of Current and Long-term Debt (Parenthetical) (Details) - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2018	Sep. 30, 2017
Debt Instrument [Line Items]
Unamortized Debt Issuance Expense, Long-Term Debt	$ 23	$ 25
Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.50%
Debt Instrument, Maturity Date	Dec. 31, 2029
Medium-term Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	9.40%
Debt Instrument, Maturity Date	Dec. 31, 2019
Notes due 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.75%
Debt Instrument, Maturity Date	Aug. 15, 2022
Term Loan B due 2024 [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	May 17, 2024
Debt Instrument, maturity year	2024
Notes due 2043 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.875%
Debt Instrument, Maturity Date	May 15, 2043
Term Loan A due 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	May 17, 2022
Debt Instrument, maturity year	2022
Term Loan A due 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	May 17, 2020
Debt Instrument, maturity year	2020

Debt - Summary of Current and Long-term Debt - Additional Information (Details) $ in Millions	Mar. 31, 2018 USD ($)
Scheduled aggregate debt maturities by fiscal year [Abstract]
2018	$ 3
2019	11
2020	269
2021	56
2022	$ 1,279

Debt - Financing Activity and Covenants - Additional Information (Details) - USD ($)	1 Months Ended		3 Months Ended	6 Months Ended		12 Months Ended
	Mar. 31, 2018	Jan. 31, 2018	Dec. 31, 2016	Mar. 31, 2018	Mar. 31, 2017	Sep. 30, 2017	Feb. 28, 2018	May 17, 2017
Debt Instrument [Line Items]
Cash repatriation		$ 300,000,000
Line of Credit Facility, Remaining Borrowing Capacity	$ 819,000,000			$ 819,000,000
Covenant restrictions [Abstract]
Maximum consolidated leverage ratio	4.5			4.5
Calculated leverage ratio	3.8			3.8
Minimum required consolidated interest coverage ratio	3.0			3.0
Calculated consolidated interest coverage ratio	4.8			4.8
Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date				Dec. 31, 2029
Par value of debt repurchases			$ 182,000,000
Debt Instrument, Interest Rate, Stated Percentage	6.50%			6.50%
Aggregate purchase price of debt			$ 177,000,000
Reduction in carrying value of debt					$ 90,000,000
Repayment of debt, accelerated accretion					92,000,000
Gain (Loss) on Repurchase of Debt Instrument					5,000,000
Term Loan A due 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 250,000,000			$ 250,000,000
Debt instrument, outstanding amount	250,000,000			$ 250,000,000
Debt instrument, term				3 years
Debt Instrument, Maturity Date				May 17, 2020
Debt Instrument, maturity year				2020
Term Loan A due 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	250,000,000			$ 250,000,000
Debt instrument, outstanding amount	250,000,000			$ 250,000,000
Debt instrument, term				5 years
Debt Instrument, Maturity Date				May 17, 2022
Debt Instrument, amortization percentage per annum (payable in equal quarterly installments)				20.00%
Debt Instrument, maturity year				2022
2017 Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	800,000,000			$ 800,000,000				$ 680,000,000
Debt instrument, term				5 years
Line of credit facility, letter of credit sublimit	$ 125,000,000			$ 125,000,000
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage						0.25%
2017 Revolving Credit Facility [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage						0.175%
2017 Revolving Credit Facility [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage						0.40%
2017 Revolving Credit Facility [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instruments, percentage points added to variable rate	1.75%			1.75%
2017 Revolving Credit Facility [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instruments, percentage points added to variable rate						1.375%
2017 Revolving Credit Facility [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instruments, percentage points added to variable rate						2.50%
2017 Revolving Credit Facility [Member] \| Alternate base rate [Member]
Debt Instrument [Line Items]
Debt instruments, percentage points added to variable rate						0.75%
2017 Revolving Credit Facility [Member] \| Alternate base rate [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instruments, percentage points added to variable rate						0.375%
2017 Revolving Credit Facility [Member] \| Alternate base rate [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instruments, percentage points added to variable rate						1.50%
Term Loan B due 2024 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 600,000,000			$ 600,000,000
Debt Instrument, Maturity Date				May 17, 2024
Debt Instrument, amortization percentage per annum (payable in equal quarterly installments)				1.00%
Debt Instrument, maturity year				2024
Term Loan B due 2024 [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instruments, percentage points added to variable rate	2.00%			2.00%
Term Loan B due 2024 [Member] \| Alternate base rate [Member]
Debt Instrument [Line Items]
Debt instruments, percentage points added to variable rate	1.00%			1.00%
Notes due 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date				Aug. 15, 2022
Debt Instrument, Interest Rate, Stated Percentage	4.75%			4.75%
Repayments of Debt					39,000,000
Notes due 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.875%			3.875%
Debt Instrument, maturity year				2018
Repayments of Debt					41,000,000
Notes due 2018 and 2022 [Member]
Debt Instrument [Line Items]
Gain (Loss) on Repurchase of Debt Instrument					$ 3,000,000
Accounts Receivable Securitization [Member]
Debt Instrument [Line Items]
Debt instrument, termination date	2018-03
Debt instrument, extended termination date	2020-03
Line of Credit Facility, Maximum Borrowing Capacity	$ 115,000,000			$ 115,000,000			$ 100,000,000
Line of Credit Facility, Remaining Borrowing Capacity	67,000,000			67,000,000
2017 Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Remaining Borrowing Capacity	752,000,000			752,000,000
Letters of Credit Outstanding, Amount	$ 48,000,000			$ 48,000,000

Income Taxes - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Income Tax Contingency [Line Items]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			21.00%	35.00%
Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount			$ 16
Increase (Decrease) in Deferred Income Taxes			126
Increase (Decrease) in Deferred Liabilities			142
Unrecognized tax benefits due to lapse of the statute of limitations		$ 4	1	$ 4
Minimum [Member]
Income Tax Contingency [Line Items]
Decrease in Unrecognized Tax Benefits is Reasonably Possible	$ 21		21
Maximum [Member]
Income Tax Contingency [Line Items]
Decrease in Unrecognized Tax Benefits is Reasonably Possible	$ 31		$ 31
Current Fiscal Year [Member]
Income Tax Contingency [Line Items]
Effective tax rate (in hundredths)	1.00%		20.00%
Current Fiscal Year [Member] \| Foreign Entity [Member]
Income Tax Contingency [Line Items]
Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount	$ (4)		$ (4)
Prior Fiscal Year [Member]
Income Tax Contingency [Line Items]
Effective tax rate (in hundredths)		(21.00%)		55.00%

Income Taxes - Summary of Changes in Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at October 1, 2017		$ 194
Increases related to positions taken on items from prior years		3
Decreases related to positions taken on items from prior years		(1)
Increases related to positions taken in the current year		6
Lapse of statute of limitations	$ (4)	(1)	$ (4)
Balance at March 31, 2018		$ 201

Employee Benefit Plans - Additional Information (Details) - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Actuarial gain	$ 0	$ 2
Foreign Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual contributions to benefit plans in period	6
Estimated future contributions in current fiscal year	2
United States Pension Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual contributions to benefit plans in period	$ 1

Employee Benefit Plans - Schedule of Components of Pension and Other Postretirement Benefit Costs for Continuing Operation (Details) - USD ($)
$ in Millions

3 Months Ended

6 Months Ended

Mar. 31, 2018

Mar. 31, 2017

Mar. 31, 2018

Mar. 31, 2017

Actuarial (gain) loss

$ 0

$ (2)

Pension Plan [Member]

Defined Benefit Plan Disclosure [Line Items]

Service cost

^[1]

$ 2

Interest cost

^[2]

Expected return on plan assets

^[2]

(3)

(2)

(6)

Actuarial (gain) loss

^[2]

Total net periodic benefit costs (income)

Other Postretirement Benefit Plan, Defined Benefit [Member]

Defined Benefit Plan Disclosure [Line Items]

Service cost

^[1]

Interest cost

^[2]

Expected return on plan assets

^[2]

Actuarial (gain) loss

^[2]

(2)

Total net periodic benefit costs (income)

$ 0

$ 1

$ (1)

[1]	Service cost was not impacted by new accounting guidance adopted in 2018 and is therefore still classified within the selling, general and administrative expense and cost of sales captions on the Statements of Consolidated Comprehensive Income (Loss). See Note A for additional information.
[2]	These components are now classified within the other net periodic benefit income caption on the Statements of Consolidated Comprehensive Income (Loss) due to the adoption of new accounting guidance in the current quarter. See Note A for additional information.

Litigation, Claims and Contingencies - Summary of Asbestos Claims Activity (Details) - Claim Claim in Thousands	6 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Ashland [Member]
Asbestos claims [Roll Forward]
Open claims - beginning of year	54	57	57	60	65
New claims filed	1	1	2	2	2
Claims settled	0	0	(1)	0	0
Claims dismissed	(2)	(2)	(4)	(5)	(7)
Open claims - end of period	53	56	54	57	60
Hercules [Member]
Asbestos claims [Roll Forward]
Open claims - beginning of year	12	15	15	20	21
New claims filed	1	1	1	1	1
Claims dismissed	(1)	(3)	(4)	(6)	(2)
Open claims - end of period	12	13	12	15	20

Litigation, Claims and Contingencies - Additional Information (Details)
$ in Millions

3 Months Ended

6 Months Ended

12 Months Ended

Mar. 31, 2018

USD ($)

Facility

WasteTreatmentorDisposalSite

ServiceStationProperty

Jun. 30, 2017

USD ($)

Mar. 31, 2018

USD ($)

Facility

WasteTreatmentorDisposalSite

ServiceStationProperty

Mar. 31, 2017

USD ($)

Sep. 30, 2017

USD ($)

Sep. 30, 2016

USD ($)

Sep. 30, 2015

USD ($)

Sep. 30, 2014

USD ($)

Environmental Remediation Costs Recognized [Abstract]

Number of waste treatment or disposal sites were company is identified as a potentially responsible party under the superfund or similar state laws | WasteTreatmentorDisposalSite

Number of current and former operating facilities subject to various environmental laws | Facility

117

Total number of service station properties subject to various environmental laws | ServiceStationProperty

1,225

Number of service stations being actively remediated | ServiceStationProperty

Accrual for environmental loss contingencies

$ 164

$ 167

$ 163

$ 177

Accrued environmental loss contingencies, noncurrent

122

121

Recorded third-party environmental recoveries receivable

Recorded third-party environmental recoveries, noncurrent

$ 13

Maximum reserve for remediation reserve related to any one site (in hundredths)

15.00%

Minimum [Member]

Number of Years Included in Asbestos Assumption

40 years

Maximum [Member]

Number of Years Included in Asbestos Assumption

50 years

Environmental Remediation Costs Recognized [Abstract]

Environmental exit costs, reasonably possible additional loss

$ 409

Increase in asbestos-related claims

$ 36

$ 0

Total reserves for asbestos claims

402

^[1]

402

^[1]

397

^[1]

419

^[1]

415

^[1]

409

^[1]

$ 438

Movement in Loss Contingency Receivable, Increase (Decrease) [Roll Forward]

149

^[2]

149

^[2]

144

^[2]

155

^[2]

151

^[2]

150

^[2]

402

(3)

Possible total future litigation defense and claim settlement costs

660

Increase in asbestos-related claims

Total reserves for asbestos claims

311

^[3]

311

^[3]

316

^[3]

323

^[3]

321

^[3]

311

^[3]

329

Movement in Loss Contingency Receivable, Increase (Decrease) [Roll Forward]

$ 77

$ 5

$ 0

$ 5

$ 7

$ 1

Possible total future litigation defense and claim settlement costs

$ 510

[1]	Included $34 million classified in accrued expenses and other liabilities on the Condensed Consolidated Balance Sheets as of March 31, 2018 and September 30, 2017.
[2]	Included $14 million classified in accounts receivable on the Condensed Consolidated Balance Sheets as of March 31, 2018 and September 30, 2017.
[3]	Included $14 million classified in accrued expenses and other liabilities on the Condensed Consolidated Balance Sheets as of March 31, 2018 and September 30, 2017.

Litigation, Claims and Contingencies - Schedule of Progression of Activity in the Asbestos Reserve (Details) - USD ($)
$ in Millions

3 Months Ended

6 Months Ended

12 Months Ended

Jun. 30, 2017

Mar. 31, 2018

Mar. 31, 2017

Sep. 30, 2017

Sep. 30, 2016

Sep. 30, 2015

Asbestos reserve - beginning of year

Asbestos reserve [Roll Forward]

$ 397

^[1]

$ 419

^[1]

$ 415

^[1]

$ 415

^[1]

$ 409

^[1]

$ 438

Reserve adjustment

Amounts paid

(17)

(18)

(32)

(31)

(29)

Asbestos reserve - end of period

^[1]

402

397

419

415

409

Asbestos reserve - beginning of year

Asbestos reserve [Roll Forward]

316

^[2]

323

^[2]

321

^[2]

321

^[2]

311

^[2]

329

Reserve adjustment

$ 16

Amounts paid

(12)

(5)

(14)

(15)

(22)

Asbestos reserve - end of period

^[2]

$ 311

$ 316

$ 323

$ 321

$ 311

[1]	Included $34 million classified in accrued expenses and other liabilities on the Condensed Consolidated Balance Sheets as of March 31, 2018 and September 30, 2017.
[2]	Included $14 million classified in accrued expenses and other liabilities on the Condensed Consolidated Balance Sheets as of March 31, 2018 and September 30, 2017.

Litigation, Claims and Contingencies - Schedule of Progression of Activity in the Asbestos Reserve (Parenthetical) (Details) - USD ($)
$ in Millions

Mar. 31, 2018

Sep. 30, 2017

Mar. 31, 2017

Sep. 30, 2016

Sep. 30, 2015

Sep. 30, 2014

Ashland [Member] | Other Current Liabilities [Member]

$ 402

^[1]

$ 419

^[1]

$ 397

^[1]

$ 415

^[1]

$ 409

^[1]

$ 438

Hercules [Member] | Other Current Liabilities [Member]

311

^[2]

323

^[2]

$ 316

^[2]

$ 321

^[2]

$ 311

^[2]

$ 329

Movement in Loss Contingency Receivable, Increase (Decrease) [Roll Forward]

$ 14

[1]	Included $34 million classified in accrued expenses and other liabilities on the Condensed Consolidated Balance Sheets as of March 31, 2018 and September 30, 2017.
[2]	Included $14 million classified in accrued expenses and other liabilities on the Condensed Consolidated Balance Sheets as of March 31, 2018 and September 30, 2017.

Litigation, Claims and Contingencies - Summary of Progression of Insurance Receivable (Details) - USD ($)
$ in Millions

3 Months Ended

6 Months Ended

12 Months Ended

Mar. 31, 2018

Jun. 30, 2017

Mar. 31, 2017

Mar. 31, 2018

Mar. 31, 2017

Sep. 30, 2017

Sep. 30, 2016

Sep. 30, 2015

Insurance settlement

^[1]

$ 1

$ 0

$ 1

$ 0

Movement in Loss Contingency Receivable, Increase (Decrease) [Roll Forward]

Insurance receivable - beginning of year

$ 144

^[2]

155

^[2]

151

^[2]

$ 151

^[2]

$ 150

^[2]

$ 402

Insurance receivable - end of period

(3)

Insurance settlement

(5)

(4)

(227)

Amounts collected

(6)

(2)

(6)

(11)

(22)

^[2]

149

144

149

144

155

151

150

Movement in Loss Contingency Receivable, Increase (Decrease) [Roll Forward]

Insurance receivable - beginning of year

Insurance receivable - end of period

$ 5

Insurance settlement

(22)

$ 68

$ 63

$ 68

$ 63

$ 68

$ 63

$ 56

[1]	Activity of $0 denotes value less than $1 million.
[2]	Included $14 million classified in accounts receivable on the Condensed Consolidated Balance Sheets as of March 31, 2018 and September 30, 2017.

Litigation, Claims and Contingencies - Summary of Progression of Insurance Receivable (Parenthetical) (Details) - Ashland [Member] - USD ($)
$ in Millions

Mar. 31, 2018

Sep. 30, 2017

Mar. 31, 2017

^[1]

Sep. 30, 2016

^[1]

Sep. 30, 2015

^[1]

Sep. 30, 2014

Movement in Loss Contingency Receivable, Increase (Decrease) [Roll Forward]

Accounts Receivable [Member]

$ 149

^[1]

$ 155

^[1]

$ 144

$ 151

$ 150

$ 402

Movement in Loss Contingency Receivable, Increase (Decrease) [Roll Forward]

Environmental Expense And Liabilities [Abstract]

$ 14

[1]	Included $14 million classified in accounts receivable on the Condensed Consolidated Balance Sheets as of March 31, 2018 and September 30, 2017.

Litigation, Claims and Contingencies - Summary of Reconciliation of Changes in Environmental Remediation Reserves (Details) - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Environmental Remediation Obligations [Abstract]
Reserve - beginning of period	$ 163	$ 177
Disbursements	(16)	(15)
Revised obligation estimates and accretion	17	5
Reserve - end of period	$ 164	$ 167

Litigation, Claims and Contingencies - Summary of Components of Environmental Remediation Expense Included within Selling, General and Administrative Expense (Details) - USD ($)
$ in Millions

3 Months Ended

6 Months Ended

Mar. 31, 2018

Mar. 31, 2017

Mar. 31, 2018

Mar. 31, 2017

Environmental expense

$ 4

$ 1

$ 16

$ 5

^[1]

(1)

Total expense, net of receivable activity

^[2]

$ 5

$ 19

$ 10

[1]

Activity of $0 denotes value less than $1 million.

[2]

Earnings Per Share - Computation of Basic and Diluted Earnings per Share (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions

3 Months Ended

6 Months Ended

Mar. 31, 2018

Mar. 31, 2017

Mar. 31, 2018

Mar. 31, 2017

Numerator

Numerator for basic and diluted EPS -Income (loss) from continuing operations

$ 66

$ 29

$ 59

$ (37)

Denominator

Denominator for basic EPS - Weighted-average common shares outstanding

Share based awards convertible to common shares

^[1]

Denominator for diluted EPS - Adjusted weighted-average shares and assumed conversions

PER SHARE DATA

Basic (in dollars per share)

$ 1.06

$ 0.46

$ 0.94

$ (0.59)

Diluted (in dollars per share)

$ 1.04

$ 0.46

$ 0.93

$ (0.59)

[1]	As a result of the loss from continuing operations attributable to Ashland during the six months ended March 31, 2017, the effect of the share-based awards convertible to common shares would be antidilutive. In accordance with U.S. GAAP, they have been excluded from the diluted EPS calculation.

The amount of net income (loss) from continuing operations per each share of common stock or unit outstanding during the reporting period.

The amount of net income (loss) derived from continuing operations during the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

Equity Items - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Apr. 30, 2015
Accelerated Share Repurchases [Line Items]
Common Stock, Dividends, Per Share, Declared	$ 0.225	$ 0.225	$ 0.225	$ 0.225	$ 0.39	$ 0.39
2015 Stock Repurchase Program [Member]
Accelerated Share Repurchases [Line Items]
Stock Repurchase Program, Authorized Amount							$ 1,000,000,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount			$ 500,000,000
2018 Stock Repurchase Program [Member]
Accelerated Share Repurchases [Line Items]
Stock Repurchase Program, Authorized Amount	$ 1,000,000,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 1,000,000,000

Equity Items - Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($)
$ in Millions

3 Months Ended

6 Months Ended

Mar. 31, 2018

Mar. 31, 2017

Mar. 31, 2018

Mar. 31, 2017

Unrealized translation gain (loss), before tax

$ 55

$ 58

$ (92)

Unrealized translation gain (loss), tax

Unrealized translation gain (loss), net of tax

(86)

Amortization of unrecognized prior service credits included in net income, before tax

(3)

^[1]

(6)

^[1]

Amortization of unrecognized prior service credits included in net income, tax

Amortization of unrecognized prior service credits included in net income, net of tax

(2)

(4)

Unrealized gain (loss) on available-for-sale securities, before taxes

(5)

Unrealized gain (loss) on available-for-sale securities, tax

(2)

(1)

(2)

Unrealized gain (loss) on available-for-sale securities, net of tax

(4)

Reclassification adjustment for gains on available-for-sale securities included in net income, before tax

(3)

(2)

(4)

(2)

Reclassification adjustment for gains on available-for-sale securities included in net income, tax

Reclassification adjustment for gains on available-for-sale securities included in net income, net of tax

(2)

(1)

(3)

(1)

Other comprehensive income (loss), before tax

(91)

Other comprehensive income (loss), tax

Other comprehensive income (loss)

$ 49

$ 64

$ 60

$ (84)

[1]

Stock Incentive Plans - Components of Stock-Based Compensation Expense Included in Continuing Operations (Details) - USD ($)
$ in Millions

3 Months Ended

6 Months Ended

Mar. 31, 2018

^[1]

Mar. 31, 2017

^[2]

Mar. 31, 2018

^[1]

Mar. 31, 2017

^[2]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Stock Appreciation Rights (SARs) [Member]

$ 9

$ 7

$ 20

$ 14

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Nonvested Stock Awards [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Performance Shares [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

$ 2

$ 6

$ 4

[1]	Included $2 million and $4 million of expense related to cash-settled nonvested restricted stock awards and $1 million and $3 million of expense related to cash-settled performance units during the three and six months ended March 31, 2018, respectively.
[2]	Included $2 million and $3 million of expense related to cash-settled nonvested restricted stock awards and $1 million and $2 million of expense related to cash-settled performance units during the three and six months ended March 31, 2017, respectively.

Stock Incentive Plans - Components of Stock-Based Compensation Expense Included in Continuing Operations (Parenthetical) (Details) - USD ($)
$ in Millions

3 Months Ended

6 Months Ended

Mar. 31, 2018

Mar. 31, 2017

Mar. 31, 2018

Mar. 31, 2017

Cash-settled Nonvested Stock Awards [Member]

$ 9

^[1]

$ 7

^[2]

$ 20

^[1]

$ 14

^[2]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Cash-settled Performance Shares [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

$ 1

$ 3

$ 2

[1]	Included $2 million and $4 million of expense related to cash-settled nonvested restricted stock awards and $1 million and $3 million of expense related to cash-settled performance units during the three and six months ended March 31, 2018, respectively.
[2]	Included $2 million and $3 million of expense related to cash-settled nonvested restricted stock awards and $1 million and $2 million of expense related to cash-settled performance units during the three and six months ended March 31, 2017, respectively.

Stock Incentive Plans - Additional Information (Details) - USD ($)
$ in Millions

3 Months Ended

6 Months Ended

Mar. 31, 2018

Mar. 31, 2017

Mar. 31, 2018

Mar. 31, 2017

Number of common shares for each converted performance share

$ 9

^[1]

$ 7

^[2]

$ 20

^[1]

$ 14

^[2]

Stock Appreciation Rights (SARs) [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Unexercised SARs lapse expiration period

10 years 1 month

Grants of share-based payment awards in period

470,000

422,000

Model to fair value share-based payment awards

$ 11

Black-Scholes option-pricing model

Unrecognized cost expected to be recognized over a weighted-average period (in years)

2 years 2 months 12 days

Stock Appreciation Rights (SARs) [Member] | Minimum [Member]

$ 2

^[1]

$ 2

^[2]

$ 3

^[1]

$ 3

^[2]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Stock Appreciation Rights (SARs) [Member] | Maximum [Member]

1 year

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Nonvested Stock Awards [Member]

3 years

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Grants of share-based payment awards in period

2,000

3,000

144,000

84,000

Unrecognized cost expected to be recognized over a weighted-average period (in years)

$ 10

2 years

Nonvested Stock Awards [Member] | Minimum [Member]

$ 5

^[1]

$ 3

^[2]

$ 11

^[1]

$ 7

^[2]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Nonvested Stock Awards [Member] | Maximum [Member]

1 year

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Cash-settled Nonvested Stock Awards [Member]

5 years

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number

3 years

229,000

Restricted Stock [Member]

$ 2

$ 4

$ 3

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number

$ 6

61,000

Performance Shares [Member]

$ 1

$ 3

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Grants of share-based payment awards in period

3 years

101,000

56,000

Unrecognized cost expected to be recognized over a weighted-average period (in years)

$ 15

2 years