CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 51	$ 42	$ 90	$ 101
Foreign currency translation adjustments:
Attributable to Meritor, Inc.	17	(10)	8	(6)
Attributable to noncontrolling interest	0	0	(1)	0
Pension and other postretirement benefit related adjustments	11	7	33	25
Unrealized gain (loss) on investments and foreign exchange contracts	(2)	3	0	5
Other comprehensive income, net of tax	26	0	40	24
Total comprehensive income	77	42	130	125
Less: Comprehensive income attributable to noncontrolling interest	(3)	(1)	(4)	(2)
Comprehensive income attributable to Meritor, Inc.	$ 74	$ 41	$ 126	$ 123