CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (34)	$ 89	$ 249	$ 255
Foreign currency translation adjustments:
Attributable to Meritor, Inc.	10	(6)	(25)	(3)
Attributable to noncontrolling interest	(2)	(1)	(2)	0
Pension and other postretirement benefit related adjustments	3	1	8	2
Unrealized loss on cash flow hedges	0	(2)	(3)	(2)
Other comprehensive income (loss), net of tax	11	(8)	(22)	(3)
Total comprehensive income (loss)	(23)	81	227	252
Less: Comprehensive income attributable to noncontrolling interest	0	(2)	(3)	(7)
Comprehensive income (loss) attributable to Meritor, Inc.	$ (23)	$ 79	$ 224	$ 245