CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 23	$ 32	$ 39	$ 59
Foreign currency translation adjustments:
Attributable to Meritor, Inc.	19	10	(9)	4
Attributable to noncontrolling interest	1	0	(1)	0
Pension and other postretirement benefit related adjustments	11	9	22	18
Unrealized gain (loss) on investments and foreign exchange contracts	1	(1)	2	2
Other comprehensive income, net of tax	32	18	14	24
Total comprehensive income	55	50	53	83
Less: Comprehensive income attributable to noncontrolling interest	(2)	0	(1)	(1)
Comprehensive income attributable to Meritor, Inc.	$ 53	$ 50	$ 52	$ 82