v3.26.1

Equity Items - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2026	Dec. 31, 2025	Mar. 31, 2025	Dec. 31, 2024	Jun. 28, 2023
Accelerated Share Repurchases [Line Items]
Dividend per common share	$ 41.5	$ 41.5	$ 40.5	$ 40.5
2023 Stock Repurchase Program [Member]
Accelerated Share Repurchases [Line Items]
Aggregate amount of common stock to be repurchased					$ 1,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 520

Amount authorized for purchase of share under share repurchase plan. Includes, but is not limited to, repurchase of stock and unit of ownership.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 505
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481520/505-30-50-4

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregate dividends paid during the period for each share of common stock outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Amount remaining authorized for purchase of share under share repurchase plan. Includes, but is not limited to, repurchase of stock and unit of ownership.

+ References

No definition available.

+ Details

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

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Namespace Prefix:
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Balance Type:
Period Type:

ASHLAND INC. 10-Q