Consolidated Statements of Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Statement of Financial Position [Abstract]
Net Sales	$ 16,526	$ 17,439	$ 16,213
Cost of sales	15,725	16,535	14,816
Gross profit	801	904	1,397
Selling, general and administrative expenses	671	730	729
Restructuring and impairment costs	176	1,181	46
Equity income (loss)	275	(13)	522
Earnings (loss) before interest and income taxes	229	(1,020)	1,144
Net financing charges	182	144	132
Other pension income (expense)	45	(43)	(49)
Income (loss) before income taxes	2	(1,121)	1,061
Income tax provision (benefit)	410	480	99
Net income (loss)	(408)	(1,601)	962
Income (loss) attributable to noncontrolling interests	83	84	85
Net income (loss) attributable to Adient	$ (491)	$ (1,685)	$ 877
Basic earnings per share (in dollars per share)	$ (5.25)	$ (18.06)	$ 9.38
Diluted earnings per share (in dollars per share)	$ (5.25)	$ (18.06)	$ 9.34
Basic shares used in computing earnings per share (in shares)	93,600,000	93,300,000	93,500,000
Diluted shares used in computing earnings per share (in shares)	93,600,000	93,300,000	93,900,000