Supplemental Guarantor Condensed Consolidating Financial Statements (Details 2) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Sep. 30, 2014	Mar. 31, 2014	Sep. 30, 2013
CURRENT ASSETS
Cash and cash equivalents	$ 207	$ 247	$ 233	$ 318
Receivables trade and other, net	545	610
Inventories	365	379
Other current assets	55	56
TOTAL CURRENT ASSETS	1,172	1,292
NET PROPERTY	387	424
GOODWILL	414	431
OTHER ASSETS	344	355
INVESTMENTS IN SUBSIDIARIES	0	0
TOTAL ASSETS	2,317	2,502
CURRENT LIABILITIES
Short-term debt	5	7
Accounts and notes payable	618	680
Other current liabilities	281	351
TOTAL CURRENT LIABILITIES	904	1,038
LONG-TERM DEBT	945	965
RETIREMENT BENEFITS	737	775
INTERCOMPANY PAYABLE (RECEIVABLE)	0	0
OTHER LIABILITIES	301	309
EQUITY (DEFICIT) ATTRIBUTABLE TO MERITOR, INC.	(596)	(612)
NONCONTROLLING INTERESTS	26	27
TOTAL LIABILITIES AND DEFICIT	2,317	2,502
Parent
CURRENT ASSETS
Cash and cash equivalents	99	71	112	144
Receivables trade and other, net	1	1
Inventories	0	0
Other current assets	9	9
TOTAL CURRENT ASSETS	109	81
NET PROPERTY	13	13
GOODWILL	0	0
OTHER ASSETS	76	75
INVESTMENTS IN SUBSIDIARIES	2,230	2,185
TOTAL ASSETS	2,428	2,354
CURRENT LIABILITIES
Short-term debt	1	1
Accounts and notes payable	48	46
Other current liabilities	98	97
TOTAL CURRENT LIABILITIES	147	144
LONG-TERM DEBT	907	916
RETIREMENT BENEFITS	636	656
INTERCOMPANY PAYABLE (RECEIVABLE)	1,287	1,198
OTHER LIABILITIES	47	52
EQUITY (DEFICIT) ATTRIBUTABLE TO MERITOR, INC.	(596)	(612)
NONCONTROLLING INTERESTS	0	0
TOTAL LIABILITIES AND DEFICIT	2,428	2,354
Guarantors
CURRENT ASSETS
Cash and cash equivalents	4	5	3	6
Receivables trade and other, net	43	45
Inventories	164	151
Other current assets	18	18
TOTAL CURRENT ASSETS	229	219
NET PROPERTY	153	158
GOODWILL	278	277
OTHER ASSETS	125	128
INVESTMENTS IN SUBSIDIARIES	341	267
TOTAL ASSETS	1,126	1,049
CURRENT LIABILITIES
Short-term debt	3	3
Accounts and notes payable	227	230
Other current liabilities	65	87
TOTAL CURRENT LIABILITIES	295	320
LONG-TERM DEBT	9	10
RETIREMENT BENEFITS	0	0
INTERCOMPANY PAYABLE (RECEIVABLE)	(1,705)	(1,736)
OTHER LIABILITIES	211	208
EQUITY (DEFICIT) ATTRIBUTABLE TO MERITOR, INC.	2,316	2,247
NONCONTROLLING INTERESTS	0	0
TOTAL LIABILITIES AND DEFICIT	1,126	1,049
Non-Guarantors
CURRENT ASSETS
Cash and cash equivalents	104	171	118	168
Receivables trade and other, net	501	564
Inventories	201	228
Other current assets	28	29
TOTAL CURRENT ASSETS	834	992
NET PROPERTY	221	253
GOODWILL	136	154
OTHER ASSETS	143	152
INVESTMENTS IN SUBSIDIARIES	0	0
TOTAL ASSETS	1,334	1,551
CURRENT LIABILITIES
Short-term debt	1	3
Accounts and notes payable	343	404
Other current liabilities	118	167
TOTAL CURRENT LIABILITIES	462	574
LONG-TERM DEBT	29	39
RETIREMENT BENEFITS	101	119
INTERCOMPANY PAYABLE (RECEIVABLE)	418	538
OTHER LIABILITIES	43	49
EQUITY (DEFICIT) ATTRIBUTABLE TO MERITOR, INC.	255	205
NONCONTROLLING INTERESTS	26	27
TOTAL LIABILITIES AND DEFICIT	1,334	1,551
Elims
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	(2,571)	(2,452)
TOTAL ASSETS	(2,571)	(2,452)
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
OTHER LIABILITIES	0	0
EQUITY (DEFICIT) ATTRIBUTABLE TO MERITOR, INC.	(2,571)	(2,452)
NONCONTROLLING INTERESTS	0	0
TOTAL LIABILITIES AND DEFICIT	$ (2,571)	$ (2,452)