CONSOLIDATED STATEMENT OF OPERATIONS - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Income Statement [Abstract]
Sales	$ 3,505	$ 3,766	$ 3,672
Cost of sales	(3,043)	(3,279)	(3,277)
GROSS MARGIN	462	487	395
Selling, general and administrative	(243)	(258)	(253)
Pension settlement losses	(59)	0	(109)
Restructuring costs	(16)	(10)	(23)
Goodwill impairment	(15)	0	0
Other operating expense, net	(1)	(2)	(3)
OPERATING INCOME	128	217	7
Other income, net	5	0	3
Gain on sale of equity investment	0	0	125
Equity in earnings of other ZF Meritor	0	190	0
Equity in earnings of affiliates	39	38	42
Interest expense, net	(105)	(130)	(126)
INCOME BEFORE INCOME TAXES	67	315	51
Provision for income taxes	(1)	(31)	(64)
INCOME (LOSS) FROM CONTINUING OPERATIONS	66	284	(13)
LOSS FROM DISCONTINUED OPERATIONS, net of tax	(1)	(30)	(7)
NET INCOME (LOSS)	65	254	(20)
Less: Net income attributable to noncontrolling interests	(1)	(5)	(2)
NET INCOME (LOSS) ATTRIBUTABLE TO MERITOR, INC.	64	249	(22)
NET INCOME (LOSS) ATTRIBUTABLE TO MERITOR, INC.
Net income (loss) from continuing operations	65	279	(15)
Loss from discontinued operations	(1)	(30)	(7)
Net income (loss)	$ 64	$ 249	$ (22)
BASIC EARNINGS (LOSS) PER SHARE
Continuing operations (in dollars per share)	$ 0.67	$ 2.86	$ (0.15)
Discontinued operations (in dollars per share)	(0.01)	(0.31)	(0.07)
Basic earnings (loss) per share (in dollars per share)	0.66	2.55	(0.22)
DILUTED EARNINGS (LOSS) PER SHARE
Continuing operations (in dollars per share)	0.65	2.81	(0.15)
Discontinued operations (in dollars per share)	(0.01)	(0.30)	(0.07)
Diluted earnings (loss) per share (in dollars per share)	$ 0.64	$ 2.51	$ (0.22)
Basic average common shares outstanding (in shares)	96.9	97.5	97.1
Diluted average common shares outstanding	100.1	99.2	97.1