Consolidated Statement of Shareholders' Equity - USD ($) $ in Millions	Total	Shareholders' Equity Attributable to Adient	Ordinary Shares, par value	Additional Paid-in Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)	Shareholders' Equity Attributable to Noncontrolling Interests
Beginning balance at Sep. 30, 2021	$ 2,718	$ 2,376	$ 0	$ 3,991	$ (988)	$ (627)	$ 342
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(75)	(120)			(120)		45
Foreign currency translation adjustments	(239)	(219)				(219)	(20)
Employee retirement plans	1	1				1
Dividends paid to and other transactions with noncontrolling interests	(53)						(53)
Purchase of subsidiary shares from noncontrolling interest	0	12		12			(12)
Share based compensation and other	23	23		23
Ending balance at Sep. 30, 2022	2,375	2,073	0	4,026	(1,108)	(845)	302
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	268	205			205		63
Foreign currency translation adjustments	(20)	(18)				(18)	(2)
Realized and unrealized gains on derivatives	21	21				21
Employee retirement plans	0
Dividends paid to and other transactions with noncontrolling interests	(45)						(45)
Repurchase and retirement of ordinary shares	(65)	(65)		(65)
Share based compensation and other	12	12		12
Ending balance at Sep. 30, 2023	2,546	2,228	0	3,973	(903)	(842)	318
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	63	18			18		45
Foreign currency translation adjustments	187	181				181	6
Realized and unrealized gains on derivatives	(32)	(32)				(32)
Employee retirement plans	0
Dividends paid to and other transactions with noncontrolling interests	(60)						(60)
Repurchase and retirement of ordinary shares	(275)	(275)		(275)
Share based compensation and other	14	14		14
Ending balance at Sep. 30, 2024	$ 2,443	$ 2,134	$ 0	$ 3,712	$ (885)	$ (693)	$ 309