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)