CONDENSED CONSOLIDATED STATEMENT OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Income Statement [Abstract]
Sales	$ 1,154	$ 983	$ 2,138	$ 1,872
Cost of sales	(1,017)	(835)	(1,874)	(1,609)
GROSS PROFIT	137	148	264	263
Selling, general and administrative	(70)	(69)	(132)	(134)
Other operating expense, net	(1)	(2)	(4)	(9)
OPERATING INCOME	66	77	128	120
Other income, net	14	23	28	37
Equity in earnings of affiliates	11	5	18	16
Interest expense, net	(12)	(17)	(25)	(45)
INCOME BEFORE INCOME TAXES	79	88	149	128
Provision for income taxes	(15)	(22)	(27)	(29)
INCOME FROM CONTINUING OPERATIONS	64	66	122	99
INCOME FROM DISCONTINUED OPERATIONS, net of tax	1	0	1	0
NET INCOME	65	66	123	99
Less: Net income attributable to noncontrolling interests	(3)	(3)	(7)	(4)
Net income	62	63	116	95
NET INCOME ATTRIBUTABLE TO MERITOR, INC.
Net income from continuing operations	61	63	115	95
Income from discontinued operations	1	0	1	0
Net income	$ 62	$ 63	$ 116	$ 95
BASIC EARNINGS PER SHARE
Continuing operations (in usd per share)	$ 0.86	$ 0.87	$ 1.63	$ 1.31
Discontinued operations (in usd per share)	0.01	0	0.01	0
Basic earnings per share (in usd per share)	0.87	0.87	1.64	1.31
DILUTED EARNINGS PER SHARE
Continuing operations (in usd per share)	0.85	0.86	1.61	1.30
Discontinued operations (in usd per share)	0.01	0	0.02	0
Diluted earnings per share (in usd per share)	$ 0.86	$ 0.86	$ 1.63	$ 1.30
Basic average common shares outstanding (in shares)	70.7	72.4	70.4	72.3
Diluted average common shares outstanding (in shares)	71.4	73.4	71.3	73.3