Equity and Noncontrolling Interests - Schedule of Stockholders Equity (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance	$ 2,718	$ 1,535
Net income (loss)	(43)	167
Foreign currency translation adjustments	19	65
Realized and unrealized gains (losses) on derivatives	(2)	28
Dividends attributable to noncontrolling interests	(8)	(4)
Purchase of subsidiary shares from noncontrolling interest	0
Share based compensation and other	(5)	8
Stockholders' equity, ending balance	2,679	1,797
Adjustments from adoption of a new standard
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance		(2)
Shareholders' Equity Attributable to Adient
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance	2,376	1,213
Net income (loss)	(54)	150
Foreign currency translation adjustments	17	55
Realized and unrealized gains (losses) on derivatives	(2)	28
Purchase of subsidiary shares from noncontrolling interest	(12)
Share based compensation and other	(5)	8
Stockholders' equity, ending balance	2,344	1,452
Shareholders' Equity Attributable to Adient | Adjustments from adoption of a new standard
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance		(2)
Ordinary Shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance	0	0
Stockholders' equity, ending balance	0	0
Additional Paid-in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance	3,991	3,974
Purchase of subsidiary shares from noncontrolling interest	(12)
Share based compensation and other	(5)	8
Stockholders' equity, ending balance	3,998	3,980
Additional Paid-in Capital | Adjustments from adoption of a new standard
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance		(2)
Retained Earnings (Accumulated Deficit)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance	(988)	(2,096)
Net income (loss)	(54)	150
Stockholders' equity, ending balance	(1,042)	(1,946)
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance	(627)	(665)
Foreign currency translation adjustments	17	55
Realized and unrealized gains (losses) on derivatives	(2)	28
Stockholders' equity, ending balance	(612)	(582)
Shareholders' Equity Attributable to Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance	342	322
Net income (loss)	11	17
Foreign currency translation adjustments	2	10
Dividends attributable to noncontrolling interests	(8)	(4)
Purchase of subsidiary shares from noncontrolling interest	(12)
Share based compensation and other	0
Stockholders' equity, ending balance	$ 335	$ 345