MERGER WITH MESA AIR GROUP, INC. - Narrative (Details) $ / shares in Units, $ in Millions		1 Months Ended
	Nov. 25, 2025 USD ($) aircraft director $ / shares shares	Feb. 09, 2026 USD ($) shares	Mar. 31, 2026 $ / shares	Dec. 31, 2025 $ / shares
Business Combination [Line Items]
Common stock, par value (in dollars per share) | $ / shares			$ 0.001	$ 0.001
Equity participation right	$ (2.3)
Republic Airways Holdings Inc.
Business Combination [Line Items]
Number of director designated | director	7
Purchase agreement term	10 years
Common stock, par value (in dollars per share) | $ / shares	$ 0.001
Share conversion rate	38.9933
Equity interest acquired, percent	88.00%
Merger related costs	$ 19.6
Proceeds from asset sales	8.4
Escrow shares (in shares) | shares		109,106
Consideration transferred	$ 120.2
Republic Airways Holdings Inc. | E175
Business Combination [Line Items]
Number of aircraft operated | aircraft	60
Republic Airways Holdings Inc. | United Airlines
Business Combination [Line Items]
Purchase agreement term	10 years
Merger funding	$ 23.6
Escrow shares (in shares) | shares		2,744,348
Start-up costs received by third party	$ 49.0
Republic Airways Holdings Inc. | Legacy Republic
Business Combination [Line Items]
Number of director designated | director	6
Common stock, par value (in dollars per share) | $ / shares	$ 0.001
Equity interest acquired, percent	88.10%
Percentage of voting interest relinquished	11.90%
Republic Airways Holdings Inc. | Mesa Air Group, Inc.
Business Combination [Line Items]
Common stock, par value (in dollars per share) | $ / shares	$ 0.001
Equity interest acquired, percent	6.00%
Escrow shares held, percent	6.00%
Shares issued (in shares) | shares	2,853,454
Republic Airways Holdings Inc. | Mesa Air Group, Inc. | United Airlines
Business Combination [Line Items]
Adjusted net debt settlement		$ 51.7
Republic Airways Holdings Inc. | United Airlines
Business Combination [Line Items]
Equity interest acquired, percent	5.90%