Fair Value Measurements (Tables)

12 Months Ended

Sep. 30, 2025

Fair Value Disclosures [Abstract]

Schedule of Fair Value Hierarchy for Assets and Liabilities

The following tables present Adient's fair value hierarchy for those assets and liabilities measured at fair value. Refer to Note 14, “Retirement Plans,” of the notes to consolidated financial statements for fair value tables of pension assets.

	Fair Value Measurements Using:
(in millions)	Total as of September 30, 2025		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Other current assets
Foreign currency exchange derivatives	$	36	$	—	$	36	$	—
Other noncurrent assets
Foreign currency exchange derivatives	1		—		1		—
Total assets	$	37	$	—	$	37	$	—
Other current liabilities
Foreign currency exchange derivatives	$	7	$	—	$	7	$	—
Cross currency interest rate swaps	1		—		1		—
Other noncurrent liabilities
Foreign currency exchange derivatives	3		—		3		—
Cross currency interest rate swaps	3		—		3		—
Total liabilities	$	14	$	—	$	14	$	—

	Fair Value Measurements Using:
(in millions)	Total as of September 30, 2024		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Other current assets
Foreign currency exchange derivatives	$	15	$	—	$	15	$	—
Other noncurrent assets
Foreign currency exchange derivatives	3		—		3		—
Total assets	$	18	$	—	$	18	$	—
Other current liabilities
Foreign currency exchange derivatives	$	32	$	—	$	32	$	—
Other noncurrent liabilities
Foreign currency exchange derivatives	9		—		9		—
Total liabilities	$	41	$	—	$	41	$	—