CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
OPERATING REVENUES:
Total operating revenues	$ 766,171	$ 789,443	$ 2,183,645	$ 2,323,680
OPERATING EXPENSES:
Salaries, wages and benefits	333,017	307,727	990,659	896,347
Aircraft maintenance, materials and repairs	178,465	183,182	483,182	506,478
Depreciation and amortization	96,560	97,433	287,878	297,427
Aircraft fuel	23,330	28,179	62,573	85,089
Airport-related expenses	18,398	17,501	53,648	54,196
Aircraft rentals	2,099	16,089	24,055	48,109
Other operating expenses	65,011	63,756	205,203	219,808
Total operating expenses	716,880	713,867	2,107,198	2,107,454
OPERATING INCOME	49,291	75,576	76,447	216,226
OTHER INCOME (EXPENSE):
Interest income	11,234	6,348	31,761	9,332
Interest expense	(32,543)	(33,283)	(99,881)	(92,308)
Other income (loss), net	(3,631)	8,112	7,544	21,011
Total other expense, net	(24,940)	(18,823)	(60,576)	(61,965)
INCOME BEFORE INCOME TAXES	24,351	56,753	15,871	154,261
PROVISION (BENEFIT) FOR INCOME TAXES	873	8,381	(955)	34,204
NET INCOME	$ 23,478	$ 48,372	$ 16,826	$ 120,057
BASIC EARNINGS PER SHARE (in dollars per share)	$ 0.56	$ 0.96	$ 0.37	$ 2.38
DILUTED EARNINGS PER SHARE (in dollars per share)	$ 0.55	$ 0.96	$ 0.37	$ 2.37
Weighted average common shares:
Basic (in shares)	41,826	50,593	45,018	50,531
Diluted (in shares)	42,580	50,636	45,540	50,636
COMPREHENSIVE INCOME:
Net income	$ 23,478	$ 48,372	$ 16,826	$ 120,057
Net unrealized appreciation (depreciation) on marketable securities, net of taxes	624	(2,624)	3,618	(4,569)
TOTAL COMPREHENSIVE INCOME	24,102	45,748	20,444	115,488
Flying agreements
OPERATING REVENUES:
Total operating revenues	741,898	763,514	2,106,130	2,245,351
Lease, airport services and other
OPERATING REVENUES:
Total operating revenues	$ 24,273	$ 25,929	$ 77,515	$ 78,329