| Document and Entity Information | May 17, 2022 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | May 17, 2022 |
| Entity Registrant Name | MERITOR, INC. |
| Entity Incorporation, State or Country Code | IN |
| Entity File Number | 1-15983 |
| Entity Tax Identification Number | 38-3354643 |
| Entity Address, Address Line One | 2135 West Maple Road |
| Entity Address, City or Town | Troy |
| Entity Address, State or Province | MI |
| Entity Address, Postal Zip Code | 48084-7186 |
| City Area Code | 248 |
| Local Phone Number | 435-1000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001113256 |
| Title of 12(b) Security | Common Stock, $1 Par Value |
| Trading Symbol | MTOR |
| Security Exchange Name | NYSE |
