XML 62 R56.htm IDEA: XBRL DOCUMENT v3.25.1
Goodwill and Other Intangible Assets - Summary of Goodwill by Reportable Segment (Parenthetical) (Details) - USD ($)
$ in Millions
 6 Months Ended
Mar. 31, 2025
Sep. 30, 2024
Goodwill [Line Items]    
Amount allocated to Avoca disposal group [1] $ 1  
Discontinued Operations, Held-for-sale [Member]    
Goodwill [Line Items]    
Amount allocated to Avoca disposal group 1  
Personal Care [Member]    
Goodwill [Line Items]    
Accumulated impairment 356 $ 356
Amount allocated to Avoca disposal group [1],[2] 1  
Specialty Additives [Member]    
Goodwill [Line Items]    
Accumulated impairment 174 174
Amount allocated to Avoca disposal group [1],[2] 0  
Intermediates [Member]    
Goodwill [Line Items]    
Accumulated impairment 90 $ 90
Amount allocated to Avoca disposal group [1],[2] $ 0  
[1] Ashland allocated $1 million to the Avoca disposal group during the six months ended March 31, 2025. See Note B of the Notes to the Condensed Consolidated Financial Statements for more information.
[2] As of March 31, 2025 and September 30, 2024, there were accumulated impairments of $356 million, $174 million and $90 million related to the Personal Care, Specialty Additives and Intermediates reportable segments, respectively.