CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 242	$ 74	$ 283	$ 166
Foreign currency translation adjustments:
Attributable to Meritor, Inc.	(56)	7	(35)	3
Attributable to noncontrolling interest	0	0	0	1
Pension and other postretirement benefit related adjustments	2	1	5	1
Unrealized loss on cash flow hedges	(5)	(1)	(3)	0
Other comprehensive income (loss), net of tax	(59)	7	(33)	5
Total comprehensive income	183	81	250	171
Less: Comprehensive income attributable to noncontrolling interest	(1)	(2)	(3)	(5)
Comprehensive income attributable to Meritor, Inc.	$ 182	$ 79	$ 247	$ 166