DOCUMENT AND ENTITY INFORMATION - shares	3 Months Ended
	Dec. 31, 2016	Feb. 01, 2017
Document and Entity Information [Abstract]
Entity registrant name	MERITOR INC
Entity central index key	0001113256
Current fiscal year end date	--09-30
Entity filer category	Large Accelerated Filer
Trading symbol	MTOR
Entity common stock, shares outstanding		88,191,038
Document period end date	Dec. 31, 2016
Document fiscal year focus	2017
Document type	10-Q
Document fiscal period focus	Q1
Amendment flag	false