Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Numerator:
Net income (loss) attributable to Adient	$ (30)	$ (71)	$ (165)	$ 148
Denominator:
Shares outstanding (in shares)	94.8	94.2	94.7	94.1
Effect of dilutive securities (in shares)	0.0	0.0	0.0	1.5
Diluted shares (in shares)	94.8	94.2	94.7	95.6
Earnings (loss) per share:
Basic (in usd per share)	$ (0.32)	$ (0.75)	$ (1.74)	$ 1.57
Diluted (in usd per share)	$ (0.32)	$ (0.75)	$ (1.74)	$ 1.55