CONDENSED CONSOLIDATED STATEMENT OF EQUITY (DEFICIT) - USD ($)	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Treasury Stock	Accumulated Other Comprehensive Loss	Total Deficit Attributable to Meritor, Inc.	Noncontrolling Interests
Beginning balance at Sep. 30, 2015	$ (646,000,000)	$ 99,000,000	$ 865,000,000	$ (814,000,000)	$ (55,000,000)	$ (766,000,000)	$ (671,000,000)	$ 25,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	83,000,000			58,000,000		24,000,000	82,000,000	1,000,000
Equity based compensation expense	6,000,000		6,000,000				6,000,000
Repurchase of common stock	(43,000,000)				(43,000,000)		(43,000,000)
Noncontrolling interest dividends	(1,000,000)							(1,000,000)
Ending Balance at Mar. 31, 2016	(601,000,000)	99,000,000	871,000,000	(756,000,000)	(98,000,000)	(742,000,000)	(626,000,000)	25,000,000
Beginning balance at Sep. 30, 2016	(186,000,000)	99,000,000	876,000,000	(241,000,000)	(136,000,000)	(809,000,000)	(211,000,000)	25,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	53,000,000			37,000,000		15,000,000	52,000,000	1,000,000
Equity based compensation expense	7,000,000		7,000,000				7,000,000
Vesting of equity based awards	0	2,000,000	(2,000,000)
Stock option exercises	2,000,000		2,000,000				2,000,000
Convertible debt with cash settlement	(13,000,000)		(13,000,000)				(13,000,000)
Repurchase of common stock		0
Noncontrolling interest dividends	(1,000,000)							(1,000,000)
Ending Balance at Mar. 31, 2017	$ (138,000,000)	$ 101,000,000	$ 870,000,000	$ (204,000,000)	$ (136,000,000)	$ (794,000,000)	$ (163,000,000)	$ 25,000,000