CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
OPERATING REVENUES:
Total operating revenues	$ 2,935,432	$ 3,004,925	$ 2,713,491
OPERATING EXPENSES:
Salaries, wages and benefits	1,322,615	1,211,551	986,664
Aircraft maintenance, materials and repairs	673,453	644,157	817,803
Depreciation and amortization	383,115	394,552	440,198
Aircraft fuel	85,913	108,456	107,057
Airport-related expenses	72,640	71,549	104,690
Aircraft rentals	25,507	75,353	63,357
Special items			84,592
Payroll support grant			(422,669)
Other operating expenses	268,120	318,145	255,932
Total operating expenses	2,831,363	2,823,763	2,437,624
OPERATING INCOME	104,069	181,162	275,867
OTHER INCOME (EXPENSE):
Interest income	43,928	17,605	1,114
Interest expense	(130,930)	(127,083)	(123,122)
Other income (loss), net	23,242	20,899	(3,249)
Total other expense, net	(63,760)	(88,579)	(125,257)
INCOME BEFORE INCOME TAXES	40,309	92,583	150,610
PROVISION FOR INCOME TAXES	5,967	19,630	38,700
NET INCOME	$ 34,342	$ 72,953	$ 111,910
BASIC EARNINGS PER SHARE (in dollars per share)	$ 0.78	$ 1.44	$ 2.22
DILUTED EARNINGS PER SHARE (in dollars per share)	$ 0.77	$ 1.44	$ 2.20
Weighted average common shares:
Basic (in shares)	43,940	50,548	50,348
Diluted (in shares)	44,599	50,644	50,753
COMPREHENSIVE INCOME:
Net income	$ 34,342	$ 72,953	$ 111,910
Net unrealized appreciation (depreciation) on marketable securities, net of taxes	4,127	(3,802)
TOTAL COMPREHENSIVE INCOME	38,469	69,151	111,910
Flying agreements
OPERATING REVENUES:
Total operating revenues	2,834,397	2,899,837	2,615,076
Lease, airport services and other
OPERATING REVENUES:
Total operating revenues	$ 101,035	$ 105,088	$ 98,415