Supplemental Guarantor Condensed Consolidating Financial Statements (Details 2) - USD ($) $ in Millions	Jun. 30, 2015	Sep. 30, 2014	Jun. 30, 2014	Sep. 30, 2013
CURRENT ASSETS
Cash and cash equivalents	$ 345	$ 247	$ 303	$ 318
Receivables trade and other, net	530	610
Inventories	365	379
Other current assets	52	56
TOTAL CURRENT ASSETS	1,292	1,292
NET PROPERTY	393	424
GOODWILL	420	431
OTHER ASSETS	348	355
INVESTMENTS IN SUBSIDIARIES	0	0
TOTAL ASSETS	2,453	2,502
CURRENT LIABILITIES
Short-term debt	18	7
Accounts and notes payable	611	680
Other current liabilities	303	351
TOTAL CURRENT LIABILITIES	932	1,038
LONG-TERM DEBT	1,079	965
RETIREMENT BENEFITS	729	775
INTERCOMPANY PAYABLE (RECEIVABLE)	0	0
OTHER LIABILITIES	304	309
EQUITY (DEFICIT) ATTRIBUTABLE TO MERITOR, INC.	(618)	(612)
NONCONTROLLING INTERESTS	27	27
TOTAL LIABILITIES AND DEFICIT	2,453	2,502
Parent
CURRENT ASSETS
Cash and cash equivalents	238	71	43	144
Receivables trade and other, net	0	1
Inventories	0	0
Other current assets	7	9
TOTAL CURRENT ASSETS	245	81
NET PROPERTY	13	13
GOODWILL	0	0
OTHER ASSETS	77	75
INVESTMENTS IN SUBSIDIARIES	2,340	2,185
TOTAL ASSETS	2,675	2,354
CURRENT LIABILITIES
Short-term debt	1	1
Accounts and notes payable	45	46
Other current liabilities	115	97
TOTAL CURRENT LIABILITIES	161	144
LONG-TERM DEBT	1,054	916
RETIREMENT BENEFITS	625	656
INTERCOMPANY PAYABLE (RECEIVABLE)	1,406	1,198
OTHER LIABILITIES	47	52
EQUITY (DEFICIT) ATTRIBUTABLE TO MERITOR, INC.	(618)	(612)
NONCONTROLLING INTERESTS	0	0
TOTAL LIABILITIES AND DEFICIT	2,675	2,354
Guarantors
CURRENT ASSETS
Cash and cash equivalents	5	5	7	6
Receivables trade and other, net	39	45
Inventories	163	151
Other current assets	18	18
TOTAL CURRENT ASSETS	225	219
NET PROPERTY	154	158
GOODWILL	277	277
OTHER ASSETS	122	128
INVESTMENTS IN SUBSIDIARIES	444	267
TOTAL ASSETS	1,222	1,049
CURRENT LIABILITIES
Short-term debt	3	3
Accounts and notes payable	222	230
Other current liabilities	67	87
TOTAL CURRENT LIABILITIES	292	320
LONG-TERM DEBT	7	10
RETIREMENT BENEFITS	0	0
INTERCOMPANY PAYABLE (RECEIVABLE)	(1,712)	(1,736)
OTHER LIABILITIES	212	208
EQUITY (DEFICIT) ATTRIBUTABLE TO MERITOR, INC.	2,423	2,247
NONCONTROLLING INTERESTS	0	0
TOTAL LIABILITIES AND DEFICIT	1,222	1,049
Non-Guarantors
CURRENT ASSETS
Cash and cash equivalents	102	171	253	168
Receivables trade and other, net	491	564
Inventories	202	228
Other current assets	27	29
TOTAL CURRENT ASSETS	822	992
NET PROPERTY	226	253
GOODWILL	143	154
OTHER ASSETS	149	152
INVESTMENTS IN SUBSIDIARIES	0	0
TOTAL ASSETS	1,340	1,551
CURRENT LIABILITIES
Short-term debt	14	3
Accounts and notes payable	344	404
Other current liabilities	121	167
TOTAL CURRENT LIABILITIES	479	574
LONG-TERM DEBT	18	39
RETIREMENT BENEFITS	104	119
INTERCOMPANY PAYABLE (RECEIVABLE)	306	538
OTHER LIABILITIES	45	49
EQUITY (DEFICIT) ATTRIBUTABLE TO MERITOR, INC.	361	205
NONCONTROLLING INTERESTS	27	27
TOTAL LIABILITIES AND DEFICIT	1,340	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	(2,784)	(2,452)
TOTAL ASSETS	(2,784)	(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	0
OTHER LIABILITIES	0	0
EQUITY (DEFICIT) ATTRIBUTABLE TO MERITOR, INC.	(2,784)	(2,452)
NONCONTROLLING INTERESTS	0	0
TOTAL LIABILITIES AND DEFICIT	$ (2,784)	$ (2,452)