Equity and Noncontrolling Interests - Schedule of Stockholders Equity (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance	$ 2,625	$ 1,842	$ 2,718	$ 1,535
Net income (loss)	(24)	(55)	(136)	199
Foreign currency translation adjustments	(148)	27	(120)	62
Realized and unrealized gains (losses) on derivatives	(7)	17	(5)	34
Dividends attributable to noncontrolling interests	(3)	(29)	(19)	(40)
Purchase of subsidiary shares from noncontrolling interest			0
Change in redeemable noncontrolling interest		(3)		(3)
Share based compensation and other	10	8	15	20
Stockholders' equity, ending balance	2,453	1,807	2,453	1,807
Shareholders' Equity Attributable to Adient
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance	2,285	1,489	2,376	1,213
Net income (loss)	(30)	(71)	(165)	148
Foreign currency translation adjustments	(135)	24	(110)	53
Realized and unrealized gains (losses) on derivatives	(7)	17	(5)	34
Purchase of subsidiary shares from noncontrolling interest			12
Share based compensation and other	10	8	15	19
Stockholders' equity, ending balance	2,123	1,467	2,123	1,467
Ordinary Shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance	0	0	0	0
Stockholders' equity, ending balance	0	0	0	0
Additional Paid-in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance	4,008	3,985	3,991	3,974
Purchase of subsidiary shares from noncontrolling interest			12
Share based compensation and other	10	8	15	19
Stockholders' equity, ending balance	4,018	3,993	4,018	3,993
Retained Earnings (Accumulated Deficit)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance	(1,123)	(1,877)	(988)	(2,096)
Net income (loss)	(30)	(71)	(165)	148
Stockholders' equity, ending balance	(1,153)	(1,948)	(1,153)	(1,948)
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance	(600)	(619)	(627)	(665)
Foreign currency translation adjustments	(135)	24	(110)	53
Realized and unrealized gains (losses) on derivatives	(7)	17	(5)	34
Stockholders' equity, ending balance	(742)	(578)	(742)	(578)
Shareholders' Equity Attributable to Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance	340	353	342	322
Net income (loss)	6	16	29	51
Foreign currency translation adjustments	(13)	3	(10)	9
Dividends attributable to noncontrolling interests	(3)	(29)	(19)	(40)
Purchase of subsidiary shares from noncontrolling interest			(12)
Change in redeemable noncontrolling interest		(3)		(3)
Share based compensation and other	0	0	0	1
Stockholders' equity, ending balance	$ 330	$ 340	$ 330	$ 340