XML 90 R81.htm IDEA: XBRL DOCUMENT
v3.22.1

Litigation, Claims and Contingencies - Summary of Asbestos Claims Activity (Details) - Claim Claim in Thousands | 6 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2022 | Mar. 31, 2021 | Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2019
Ashland [Member] |  |  |  |  |
Asbestos claims [Roll Forward] |  |  |  |  |
Open claims - beginning of year | 46 | 49 | 49 | 53 | 53
New claims filed | 1 | 1 | 2 | 2 | 2
Claims settled | (1) | 0 | (1) | (1) | (1)
Claims dismissed | (1) | (3) | (4) | (5) | (1)
Open claims - end of period | 45 | 47 | 46 | 49 | 53
Hercules [Member] |  |  |  |  |
Asbestos claims [Roll Forward] |  |  |  |  |
Open claims - beginning of year | 12 | 12 | 12 | 13 | 13
New claims filed | 1 | 1 | 1 | 1 | 1
Claims dismissed | (1) | (1) | (1) | (2) | (1)
Open claims - end of period | 12 | 12 | 12 | 12 | 13

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | ash_AsbestosClaimsRollForward
Namespace Prefix: | ash_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of claims dismissed. + References No definition available. + Details
Name: | us-gaap_LossContingencyClaimsDismissedNumber
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of claims settled. + References No definition available. + Details
Name: | us-gaap_LossContingencyClaimsSettledNumber
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The total number of new claims filed pertaining to a loss contingency during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14435-108349 + Details
Name: | us-gaap_LossContingencyNewClaimsFiledNumber
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of pending claims pertaining to a loss contingency. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14435-108349 + Details
Name: | us-gaap_LossContingencyPendingClaimsNumber
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | dei_LegalEntityAxis=ash_AshlandGlobalHoldingsIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=ash_HerculesLimitedLiabilityCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |