Consolidated Statements of Income (Loss) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Net Sales	$ 13,680	$ 12,670	$ 16,526
Cost of sales	12,854	12,078	15,725
Gross profit	826	592	801
Selling, general and administrative expenses	537	558	671
Loss on business divestitures - net	26	13	0
Restructuring and impairment costs	21	238	176
Equity income (loss)	1,484	22	275
Earnings (loss) before interest and income taxes	1,726	(195)	229
Net financing charges	311	220	182
Other pension expense (income)	(24)	14	45
Income (loss) before income taxes	1,439	(429)	2
Income tax provision (benefit)	249	57	410
Net income (loss)	1,190	(486)	(408)
Income (loss) attributable to noncontrolling interests	82	61	83
Net income (loss) attributable to Adient	$ 1,108	$ (547)	$ (491)
Earnings per share:
Basic (in dollars per share)	$ 11.76	$ (5.83)	$ (5.25)
Diluted (in dollars per share)	$ 11.58	$ (5.83)	$ (5.25)
Shares used in computing earnings per share:
Basic (in shares)	94.2	93.8	93.6
Diluted (in shares)	95.7	93.8	93.6