CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (LOSS) Statement (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 254	$ (20)	$ 63
Other comprehensive income (loss):
Foreign currency translation adjustments	(20)	(32)	(18)
Pension and other postretirement benefit related adjustments (net of tax of $2, $12 and $2 at September 30, 2014, 2013 and 2012, respectively)	3	218	(68)
Unrealized gain (loss) on investments and foreign exchange contracts	2	(5)	1
Reclassification adjustment for gain on sale of investments	0	0	(2)
Total comprehensive income (loss)	239	161	(24)
Less: Comprehensive income attributable to noncontrolling interest	(5)	(2)	(10)
Comprehensive income (loss) attributable to Meritor, Inc.	$ 234	$ 159	$ (34)