Acquisitions and Divestitures (Details) ¥ in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Dec. 31, 2023 CNY (¥)
Disposed of By Sale | Adient (Langfang) Seating Co., Ltd
Business Combination [Line Items]
Subsidiary, ownership percentage disposed		51.00%		51.00%	51.00%
Consideration for disposal group		$ 6			¥ 44
Deconsolidated cash		9
Loss on disposal		8		$ 8
Disposed of By Sale | Adient (Langfang) Seating Co., Ltd | Asia
Business Combination [Line Items]
Goodwill		$ 5
Assets Held For Sale | Adient (Langfang) Seating Co., Ltd
Business Combination [Line Items]
Subsidiary, ownership percentage disposed		100.00%			100.00%
Setex, Inc.
Business Combination [Line Items]
Proceeds from sale of investments	$ 27
Gain on sale	4		$ 4
Technotrim, Inc.
Business Combination [Line Items]
Net purchase consideration	$ 28