Summary of Significant Accounting Policies - Schedule of Original Cost of Company's Fixed Assets and Accumulated Depreciation or Amortization (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Property, Plant And Equipment, Excluding Construction In Progress
Property, Plant, and Equipment [Line Items]
Original Cost	$ 238,507	$ 262,158
Accumulated Depreciation/ Amortization	204,936	217,938
Aircraft
Property, Plant, and Equipment [Line Items]
Original Cost	55,464	65,480
Accumulated Depreciation/ Amortization	48,822	55,544
Spare engines
Property, Plant, and Equipment [Line Items]
Original Cost	144,559	157,997
Accumulated Depreciation/ Amortization	128,588	135,278
Rotable parts
Property, Plant, and Equipment [Line Items]
Original Cost	29,696	29,823
Accumulated Depreciation/ Amortization	19,441	19,223
Ground equipment
Property, Plant, and Equipment [Line Items]
Original Cost	2,926	2,953
Accumulated Depreciation/ Amortization	2,605	2,466
Office equipment
Property, Plant, and Equipment [Line Items]
Original Cost	4,800	4,782
Accumulated Depreciation/ Amortization	4,600	4,547
Leasehold improvements
Property, Plant, and Equipment [Line Items]
Original Cost	1,062	1,123
Accumulated Depreciation/ Amortization	$ 880	$ 880