Segment Information (Details) $ in Millions				3 Months Ended				9 Months Ended
	Jun. 24, 2020 USD ($)	Jan. 31, 2020 USD ($)	Oct. 25, 2019 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)	Jun. 30, 2021 USD ($) segment	Jun. 30, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment								3
Net sales				$ 3,242		$ 1,626		$ 10,909	$ 9,073
Other items				26		(4)		28	(12)
Restructuring and impairment costs				(8)		(49)		(20)	(103)
Purchase accounting amortization				(11)		(9)		(32)	(30)
Restructuring related charges				0		(5)		(6)	(17)
Loss on business divestitures - net				0		0		0	(25)
Gain on sale / (impairment) of nonconsolidated partially-owned affiliates				0		(6)		33	(222)
Depreciation				(71)		(67)		(210)	(214)
Stock based compensation				(10)		(7)		(36)	(8)
Earnings (loss) before interest and income taxes				44		(269)		556	(245)
Net financing charges				(87)		(58)		(256)	(156)
Other pension income (expense)				4		1		8	5
Income (loss) before income taxes				(39)		(326)		308	(396)
Non-cash impairment charges	$ 6							11	27
Loss on business divestitures - net				0		0		0	25
Gain on sale of joint venture				33	$ 33			33	(222)
Integration-related costs				2		4		13	11
Tax adjustments				$ (28)				$ (36)
Tax credits, recovery period				20 years				20 years
China
Segment Reporting Information [Line Items]
Net sales				$ 171		130		$ 525	372
Non-cash impairment charges						27			27
BRAZIL
Segment Reporting Information [Line Items]
Tax adjustments				(30)				(38)
Adient Aerospace
Segment Reporting Information [Line Items]
Loss on business divestitures - net									(4)
YFAS
Segment Reporting Information [Line Items]
Gain on previously held interest								5
YFAI
Segment Reporting Information [Line Items]
Non-cash impairment charges	$ 9	$ 216				6	$ 216
Tax adjustments									1
Americas | Adient Aerospace
Segment Reporting Information [Line Items]
Loss on business divestitures - net			$ (4)
Americas | RECARO
Segment Reporting Information [Line Items]
Loss on business divestitures - net									21
EMEA
Segment Reporting Information [Line Items]
Non-cash impairment charges				1				9
Asia
Segment Reporting Information [Line Items]
Non-cash impairment charges						27
Operating segments | Americas
Segment Reporting Information [Line Items]
Net sales				1,440		593		4,821	4,093
Adjusted EBITDA				23		(83)		219	117
Operating segments | EMEA
Segment Reporting Information [Line Items]
Net sales				1,328		698		4,568	3,750
Adjusted EBITDA				22		(94)		277	17
Operating segments | Asia
Segment Reporting Information [Line Items]
Net sales				516		346		1,658	1,362
Adjusted EBITDA				92		71		364	311
Eliminations
Segment Reporting Information [Line Items]
Net sales				(42)		(11)		(138)	(132)
Corporate-related costs
Segment Reporting Information [Line Items]
Other items				$ (19)		$ (16)		$ (61)	$ (59)