Employee Stock Purchase Plan	3 Months Ended
Dec. 31, 2024
Share-Based Payment Arrangement [Abstract]
Employee Stock Purchase Plan	14. Employee Stock Purchase Plan 2019 ESPP The Mesa Air Group, Inc. 2019 Employee Stock Purchase Plan (the "2019 ESPP") is a nonqualified plan that provides eligible employees of Mesa Air Group, Inc. with an opportunity to purchase Mesa Air Group, Inc. ordinary shares through payroll deductions. Under the 2019 ESPP, eligible employees may elect to contribute 1% to 15% of their eligible compensation during each semi-annual offering period to purchase Mesa Air Group, Inc. ordinary shares at a 10% discount. A maximum of 500,000 Mesa Air Group, Inc. ordinary shares may be issued under the 2019 ESPP. As of December 31, 2024, eligible employees purchased and the Company issued an aggregate of 499,962 Mesa Air Group, Inc. ordinary shares under the 2019 ESPP. During the fiscal year ended September 30, 2024, the maximum amount of shares was reached and the 2019 ESPP was discontinued.

The entire disclosure for shareholders' equity and share-based payment arrangement. Includes, but is not limited to, disclosure of policy and terms of share-based payment arrangement, deferred compensation arrangement, and employee stock purchase plan (ESPP).

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 718
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/718/tableOfContent

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 505
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/505/tableOfContent

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