Accelerated amortization of debt issuance costs, accretion on debt discounts and premiums and bond tender premium.

No definition available.

Name:	ash_AcceleratedAmortizationOfDebtIssuanceCostsAccretionOnDebtDiscountsAndPremiumsAndBondTenderPremium
Namespace Prefix:	ash_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Debt instrument maturity year.

+ References

No definition available.

+ Details

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Namespace Prefix:	ash_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration

- Definition

The maximum consolidated leverage ratio permitted under the debt instruments.

+ References

No definition available.

+ Details

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Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- Definition

The minimum required consolidated interest coverage ratio under the debt instruments.

+ References

No definition available.

+ Details

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Data Type:	xbrli:decimalItemType
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Period Type:	instant

- Definition

Tender offer aggregate purchase price.

+ References

No definition available.

+ Details

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Namespace Prefix:	ash_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash outflow for the extinguishment of long-term borrowing, with the highest claim on the assets of the entity in case of bankruptcy or liquidation, before its maturity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3291-108585

+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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Period Type:	duration

- Details

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- Details

Name:	us-gaap_DebtInstrumentAxis=ash_NotesDue2043Member
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Period Type:

- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

Name:	us-gaap_CreditFacilityAxis=ash_UnsecuredDelayedDrawTermLoanFacilityMember
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Subsequent Events - Additional Information (Details)		1 Months Ended	3 Months Ended
Subsequent Events - Additional Information (Details)	Jan. 31, 2020 USD ($)	Jan. 31, 2020 USD ($)	Dec. 31, 2019	Jan. 31, 2020 EUR (€)
Subsequent Event [Line Items]
Maximum consolidated leverage ratio			4.5
Minimum required consolidated interest coverage ratio			3.0
Notes due 2022 [Member]
Subsequent Event [Line Items]
Debt instrument, interest rate, stated percentage			4.75%
Debt instrument, maturity year			2022
Notes due 2043 [Member]
Subsequent Event [Line Items]
Debt instrument, interest rate, stated percentage			6.875%
Debt instrument, maturity year			2043
Subsequent Event [Member]
Subsequent Event [Line Items]
Maximum consolidated leverage ratio	4.0	4.0		4.0
Minimum required consolidated interest coverage ratio	3.0	3.0		3.0
Subsequent Event [Member] \| Minimum [Member]
Subsequent Event [Line Items]
Accelerated amortization of debt issuance costs, accretion on debt discounts and premiums and bond tender premium	$ 60,000,000	$ 60,000,000
Subsequent Event [Member] \| Senior Unsecured Notes Due 2028 [Member]
Subsequent Event [Line Items]
Debt instrument, interest rate, stated percentage	2.00%	2.00%		2.00%
Aggregate principal amount \| €				€ 500,000,000
Subsequent Event [Member] \| Notes due 2022 [Member]
Subsequent Event [Line Items]
Debt instrument, interest rate, stated percentage	4.75%	4.75%		4.75%
Debt instrument, maturity year	2022
Early settlement of principal amount	$ 671,000,000
Subsequent Event [Member] \| Notes due 2022 [Member] \| Maximum [Member]
Subsequent Event [Line Items]
Aggregate purchase price	$ 712,000,000	$ 712,000,000
Subsequent Event [Member] \| Notes due 2043 [Member]
Subsequent Event [Line Items]
Debt instrument, interest rate, stated percentage	6.875%	6.875%		6.875%
Debt instrument, maturity year	2043
Early settlement of principal amount	$ 92,000,000
Subsequent Event [Member] \| Notes due 2043 [Member] \| Maximum [Member]
Subsequent Event [Line Items]
Aggregate purchase price	$ 113,000,000	$ 113,000,000
Subsequent Event [Member] \| Debentures due 2027 [Member]
Subsequent Event [Line Items]
Debt instrument, interest rate, stated percentage	6.60%	6.60%		6.60%
Debt instrument, maturity year	2027
Subsequent Event [Member] \| Debentures due 2027 [Member] \| Maximum [Member]
Subsequent Event [Line Items]
Early settlement of principal amount	$ 1,000,000
Aggregate purchase price	$ 113,000,000	$ 113,000,000
Subsequent Event [Member] \| Junior Subordinated Debentures due 2029 [Member]
Subsequent Event [Line Items]
Debt instrument, interest rate, stated percentage	6.50%	6.50%		6.50%
Debt instrument, maturity year	2029
Early settlement of principal amount	$ 3,000,000
Subsequent Event [Member] \| Junior Subordinated Debentures due 2029 [Member] \| Maximum [Member]
Subsequent Event [Line Items]
Aggregate purchase price	113,000,000	$ 113,000,000
Unsecured Revolving Credit Facility [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Unsecured line of credit	600,000,000	$ 600,000,000
Debt instrument, term		5 years
Unsecured Delayed Draw Term Loan Facility [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Unsecured line of credit	$ 250,000,000	$ 250,000,000
Debt instrument, term		5 years