Business Segment Information (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Mar. 31, 2015		Mar. 31, 2014		Mar. 31, 2015		Mar. 31, 2014
Segment Reporting Information [Line Items]
Segment EBITDA	$ 87		$ 81	[1]	$ 168		$ 155
Unallocated legacy and corporate costs, net	0	[2]	(1)	[1],[2]	(2)	[2]	(3)	[2]
Interest expense, net	(21)		(48)	[1]	(40)		(75)
Provision for income taxes	(6)		(8)	[1]	(13)		(19)
Depreciation and amortization	(17)		(17)	[1]	(32)		(33)
Noncontrolling interests	0		(2)	[1]	(1)		(4)
Loss on sale of receivables	(1)		(2)	[1]	(3)		(5)
Restructuring costs	(3)		(2)	[1]	(6)		(3)
Income (loss) from continuing operations attributable to Meritor, Inc.	39		1	[1]	71		13
Commercial Truck & Industrial
Segment Reporting Information [Line Items]
Segment EBITDA	57		57	[1]	113		110
Aftermarket & Trailer
Segment Reporting Information [Line Items]
Segment EBITDA	$ 30		$ 24	[1]	$ 55		$ 45

[1] Amounts for prior periods have been recast for discontinued operations.

[2] Unallocated legacy and corporate costs, net represents items that are not directly related to the company's business segments. These costs primarily include asbestos-related charges, pension and retiree medical costs associated with sold businesses and other legacy costs for environmental and product liability.