SUPPLEMENTAL PARENT AND GUARANTOR CONDENSED CONSOLIDATING FINANCIAL STATEMENTS (Details 2) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
CURRENT ASSETS
Cash and cash equivalents	$ 247	$ 318	$ 257	$ 217
Receivables trade and other, net	610	596
Inventories	379	414
Other current assets	56	56
TOTAL CURRENT ASSETS	1,292	1,384
NET PROPERTY	424	417
GOODWILL	431	434	433
OTHER ASSETS	355	335
INVESTMENTS IN SUBSIDIARIES	0	0
TOTAL ASSETS	2,502	2,570
CURRENT LIABILITIES
Short-term debt	7	13
Accounts and notes payable	680	694
Other current liabilities	351	339
TOTAL CURRENT LIABILITIES	1,038	1,046
LONG-TERM DEBT	965	1,125
RETIREMENT BENEFITS	775	886
INTERCOMPANY PAYABLE (RECEIVABLE)	0	0
OTHER LIABILITIES	309	335
EQUITY (DEFICIT) ATTRIBUTABLE TO MERITOR, INC.	(612)	(850)
NONCONTROLLING INTERESTS	27	28
TOTAL LIABILITIES AND DEFICIT	2,502	2,570
Parent [Member]
CURRENT ASSETS
Cash and cash equivalents	71	144	91	92
Receivables trade and other, net	1	1
Inventories	0
Other current assets	9	4
TOTAL CURRENT ASSETS	81	149
NET PROPERTY	13	10
GOODWILL	0	0
OTHER ASSETS	75	77
INVESTMENTS IN SUBSIDIARIES	2,185	1,718
TOTAL ASSETS	2,354	1,954
CURRENT LIABILITIES
Short-term debt	1	5
Accounts and notes payable	46	51
Other current liabilities	97	95
TOTAL CURRENT LIABILITIES	144	151
LONG-TERM DEBT	916	1,088
RETIREMENT BENEFITS	656	775
INTERCOMPANY PAYABLE (RECEIVABLE)	1,198	723
OTHER LIABILITIES	52	67
EQUITY (DEFICIT) ATTRIBUTABLE TO MERITOR, INC.	(612)	(850)
NONCONTROLLING INTERESTS	0	0
TOTAL LIABILITIES AND DEFICIT	2,354	1,954
Guarantors [Member]
CURRENT ASSETS
Cash and cash equivalents	5	6	3	4
Receivables trade and other, net	45	24
Inventories	151	164
Other current assets	18	17
TOTAL CURRENT ASSETS	219	211
NET PROPERTY	158	145
GOODWILL	277	277
OTHER ASSETS	128	134
INVESTMENTS IN SUBSIDIARIES	267	109
TOTAL ASSETS	1,049	876
CURRENT LIABILITIES
Short-term debt	3	7
Accounts and notes payable	230	199
Other current liabilities	87	76
TOTAL CURRENT LIABILITIES	320	282
LONG-TERM DEBT	10	8
RETIREMENT BENEFITS	0	0
INTERCOMPANY PAYABLE (RECEIVABLE)	(1,736)	(1,412)
OTHER LIABILITIES	208	204
EQUITY (DEFICIT) ATTRIBUTABLE TO MERITOR, INC.	2,247	1,794
NONCONTROLLING INTERESTS	0	0
TOTAL LIABILITIES AND DEFICIT	1,049	876
Non-Guarantors [Member]
CURRENT ASSETS
Cash and cash equivalents	171	168	163	121
Receivables trade and other, net	564	571
Inventories	228	250
Other current assets	29	35
TOTAL CURRENT ASSETS	992	1,024
NET PROPERTY	253	262
GOODWILL	154	157
OTHER ASSETS	152	124
INVESTMENTS IN SUBSIDIARIES	0	0
TOTAL ASSETS	1,551	1,567
CURRENT LIABILITIES
Short-term debt	3	1
Accounts and notes payable	404	444
Other current liabilities	167	168
TOTAL CURRENT LIABILITIES	574	613
LONG-TERM DEBT	39	29
RETIREMENT BENEFITS	119	111
INTERCOMPANY PAYABLE (RECEIVABLE)	538	689
OTHER LIABILITIES	49	64
EQUITY (DEFICIT) ATTRIBUTABLE TO MERITOR, INC.	205	33
NONCONTROLLING INTERESTS	27	28
TOTAL LIABILITIES AND DEFICIT	1,551	1,567
Elims [Member]
CURRENT ASSETS
Cash and cash equivalents	0	0	0	0
Receivables trade and other, net	0	0
Inventories	0	0
Other current assets	0	0
TOTAL CURRENT ASSETS	0	0
NET PROPERTY	0	0
GOODWILL	0	0
OTHER ASSETS	0	0
INVESTMENTS IN SUBSIDIARIES	(2,452)	(1,827)
TOTAL ASSETS	(2,452)	(1,827)
CURRENT LIABILITIES
Short-term debt	0	0
Accounts and notes payable	0	0
Other current liabilities	0	0
TOTAL CURRENT LIABILITIES	0	0
LONG-TERM DEBT	0	0
RETIREMENT BENEFITS	0	0
INTERCOMPANY PAYABLE (RECEIVABLE)	0	0
OTHER LIABILITIES	0	0
EQUITY (DEFICIT) ATTRIBUTABLE TO MERITOR, INC.	(2,452)	(1,827)
NONCONTROLLING INTERESTS	0	0
TOTAL LIABILITIES AND DEFICIT	$ (2,452)	$ (1,827)