CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 58	$ 33
Foreign currency translation adjustments:
Attributable to Meritor, Inc.	(14)	55
Attributable to noncontrolling interests	0	1
Pension and other postretirement benefit related adjustments	1	3
Unrealized gain on cash flow hedges	1	1
Other comprehensive income (loss), net of tax	(12)	60
Total comprehensive income	46	93
Less: Comprehensive income attributable to noncontrolling interests	(4)	(2)
Comprehensive income attributable to Meritor, Inc.	$ 42	$ 91