| Document And Entity Information | Jun. 18, 2024 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jun. 18, 2024 |
| Entity Registrant Name | Mesa Air Group, Inc. |
| Entity Central Index Key | 0000810332 |
| Entity Emerging Growth Company | false |
| Entity File Number | 001-38626 |
| Entity Incorporation, State or Country Code | NV |
| Entity Tax Identification Number | 85-0302351 |
| Entity Address, Address Line One | 410 North 44th Street |
| Entity Address, Address Line Two | Suite 700 |
| Entity Address, City or Town | Phoenix |
| Entity Address, State or Province | AZ |
| Entity Address, Postal Zip Code | 85008 |
| City Area Code | (602) |
| Local Phone Number | 685-4000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre commencement Tender Offer | false |
| Pre commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, no par value |
| Trading Symbol | MESA |
| Security Exchange Name | NASDAQ |
