CONSOLIDATED STATEMENT OF EQUITY (DEFICIT) (USD $) In Millions, unless otherwise specified	Total	Total Deficit Attributable to Meritor, Inc. [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interests [Member]
Beginning balance at Sep. 30, 2011	$ (961)	$ (995)	$ 94	$ 897	$ (1,157)	$ (829)	$ 34
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	(24)	(34)			52	(86)	10
Equity based compensation expense	6	6		6
Vesting of restricted stock	0		2	(2)
Non-controlling interest dividends	(3)						(3)
Ending Balance at Sep. 30, 2012	(982)	(1,023)	96	901	(1,105)	(915)	41
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	161	159			(22)	181	2
Equity based compensation expense	5	5		5
Vesting of restricted stock	0		1	(1)
Repurchase of convertible notes	(2)	(2)		(2)
Issuance of convertible notes	9	9		9
Non-controlling interest dividends	(15)						(15)
Other	2	2		2
Ending Balance at Sep. 30, 2013	(822)	(850)	97	914	(1,127)	(734)	28
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	239	234			249	(15)	5
Equity based compensation expense	8	8		8
Repurchase of convertible notes	(4)	(4)		(4)
Non-controlling interest dividends	(6)						(6)
Ending Balance at Sep. 30, 2014	$ (585)	$ (612)	$ 97	$ 918	$ (878)	$ (749)	$ 27