CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 296	$ 126	$ 328
Other comprehensive income:
Foreign currency translation adjustments	(18)	(51)	25
Pension and other postretirement benefit related adjustments (net of tax of $22, $6 and $147 for the year ended September 30, 2019, 2018 and 2017, respectively)	(96)	24	240
Unrealized gain (loss) on cash flow hedges	(2)	4	(1)
Total comprehensive income	180	103	592
Less: Comprehensive income attributable to noncontrolling interest	(4)	(7)	(4)
Comprehensive income attributable to Meritor, Inc.	$ 176	$ 96	$ 588