SUPPLEMENTAL PARENT AND GUARANTOR CONDENSED CONSOLIDATING FINANCIAL STATEMENTS SUPPLEMENTAL PARENT AND GUARANTOR CONDENSED CONSOLIDATING FINANCIAL STATEMENTS (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
Condensed Financial Statements, Captions [Line Items]
Net income (loss)	$ 4	$ 234	$ 3	$ 13	$ 43	$ (39)	$ (4)	$ (20)	$ 254	$ (20)	$ 63
Other comprehensive income (loss)									(15)	181	(87)
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)
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Net income (loss)									249	(22)	52
Other comprehensive income (loss)									(15)	181	(86)
Total comprehensive income (loss)									234	159	(34)
Less: Comprehensive income attributable to noncontrolling interest									0	0	0
Comprehensive income (loss) attributable to Meritor, Inc.									234	159	(34)
Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net income (loss)									479	281	255
Other comprehensive income (loss)									(54)	13	(41)
Total comprehensive income (loss)									425	294	214
Less: Comprehensive income attributable to noncontrolling interest									0	0	0
Comprehensive income (loss) attributable to Meritor, Inc.									425	294	214
Non-Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net income (loss)									79	(162)	60
Other comprehensive income (loss)									25	(12)	(1)
Total comprehensive income (loss)									104	(174)	59
Less: Comprehensive income attributable to noncontrolling interest									(5)	(2)	(10)
Comprehensive income (loss) attributable to Meritor, Inc.									99	(176)	49
Elims [Member]
Condensed Financial Statements, Captions [Line Items]
Net income (loss)									(553)	(117)	(304)
Other comprehensive income (loss)									29	(1)	41
Total comprehensive income (loss)									(524)	(118)	(263)
Less: Comprehensive income attributable to noncontrolling interest									0	0	0
Comprehensive income (loss) attributable to Meritor, Inc.									$ (524)	$ (118)	$ (263)