CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 65	$ 66	$ 123	$ 99
Foreign currency translation adjustments:
Attributable to Meritor, Inc.	15	(22)	1	33
Attributable to noncontrolling interests	0	(1)	0	0
Pension and other postretirement benefit related adjustments	2	2	3	5
Unrealized gain on cash flow hedges	(1)	0	0	1
Other comprehensive income (loss), net of tax	16	(21)	4	39
Total comprehensive income	81	45	127	138
Less: Comprehensive income attributable to noncontrolling interests	(3)	(2)	(7)	(4)
Comprehensive income attributable to Meritor, Inc.	$ 78	$ 43	$ 120	$ 134