Consolidated Statements of Income (Loss) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Net sales	$ 3,819	$ 3,511	$ 7,667	$ 7,447
Cost of sales	3,521	3,274	7,028	6,947
Gross profit	298	237	639	500
Selling, general and administrative expenses	148	127	297	292
Loss on business divestitures - net	0	0	0	25
Restructuring and impairment costs	5	52	12	54
Equity income (loss)	85	8	182	(105)
Earnings (loss) before interest and income taxes	230	66	512	24
Net financing charges	110	50	169	98
Other pension expense (income)	(2)	(2)	(4)	(4)
Income (loss) before income taxes	122	18	347	(70)
Income tax provision (benefit)	28	16	80	70
Net income (loss)	94	2	267	(140)
Income (loss) attributable to noncontrolling interests	25	21	48	46
Net income (loss) attributable to Adient	$ 69	$ (19)	$ 219	$ (186)
Earnings (loss) per share:
Basic (in dollars per share)	$ 0.73	$ (0.20)	$ 2.33	$ (1.98)
Diluted (in dollars per share)	$ 0.72	$ (0.20)	$ 2.30	$ (1.98)
Shares used in computing earnings per share:
Basic (in shares)	94.2	93.8	94.1	93.8
Diluted (in shares)	96.0	93.8	95.4	93.8