BUSINESS SEGMENT INFORMATION (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2012
Segment Reporting Information [Line Items]
Segment EBITDA									$ 324		$ 279		$ 351
Unallocated legacy and corporate expense, net									(10)	[1]	(15)	[1]	(24)	[1]
Interest expense, net									(130)		(126)		(95)
Provision for income taxes	0	(12)	(8)	(11)	(45)	(1)	(7)	(11)	(31)		(64)		(57)
Depreciation and amortization									(67)		(67)		(63)
Loss on sale of receivables									(8)		(6)		(9)
Restructuring costs	(7)		(2)	(1)		(12)	(11)	(3)	(10)		(23)		(39)
Litigation Settlement, Amount, After Taxes And Fees Incurred In Current Fiscal Year									208	[2]	0	[2]	0	[2]
Specific warranty contingency, net of supplier recovery									8		(7)		0
Pension settlement losses					(73)	(36)			0		(109)		0
Gain on sale of equity investment									0		125		0
Gain on sale of property									0		0		16
Noncontrolling interests									(5)		(2)		(11)
Income (loss) from continuing operations attributable to Meritor, Inc.	29	237	1	12	40	(37)	(3)	(15)	279		(15)		69
Commercial Truck & Industrial [Member]
Segment Reporting Information [Line Items]
Segment EBITDA									218		192		270
Depreciation and amortization									(61)	[3]	(60)	[3]	(58)	[3]
Restructuring costs									(8)		(17)		(36)
Aftermarket & Trailer [Member]
Segment Reporting Information [Line Items]
Segment EBITDA									106		87		81
Depreciation and amortization									(6)	[3]	(7)	[3]	(5)	[3]
Restructuring costs									$ (1)		$ (3)		$ (2)

[1] 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 associated with the company's year-end liability remeasurement, pension and retiree medical costs associated with sold businesses and other legacy costs for environmental and product liability. In fiscal year 2013, unallocated legacy and corporate costs, net includes approximately $4 million of executive severance related to the company's former Chief Executive Officer.

[2] Adjustment associated with the company's share of the antitrust settlement with Eaton less legal expenses incurred in fiscal year 2014.

[3] In fiscal year 2013, the company reorganized its management structure resulting in two reportable segments. Prior period segment financial information presented has been recast to reflect the revised reporting structure.