CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
OPERATING REVENUES:
Total operating revenues	$ 725,643	$ 799,085	$ 1,417,474	$ 1,534,237
OPERATING EXPENSES:
Salaries, wages and benefits	322,441	288,562	657,642	588,620
Aircraft maintenance, materials and repairs	162,491	174,883	304,717	323,296
Depreciation and amortization	97,169	97,249	191,318	199,994
Aircraft fuel	18,279	31,820	39,243	56,910
Airport-related expenses	16,955	17,490	35,250	36,695
Aircraft rentals	2,428	16,024	21,956	32,020
Other operating expenses	74,020	84,455	140,192	156,052
Total operating expenses	693,783	710,483	1,390,318	1,393,587
OPERATING INCOME	31,860	88,602	27,156	140,650
OTHER INCOME (EXPENSE):
Interest income	10,494	2,559	20,527	2,984
Interest expense	(33,718)	(30,433)	(67,338)	(59,025)
Other income, net	9,001	12,019	11,175	12,899
Total other expense, net	(14,223)	(15,855)	(35,636)	(43,142)
INCOME (LOSS) BEFORE INCOME TAXES	17,637	72,747	(8,480)	97,508
PROVISION (BENEFIT) FOR INCOME TAXES	2,218	18,796	(1,828)	25,823
NET INCOME (LOSS)	$ 15,419	$ 53,951	$ (6,652)	$ 71,685
BASIC EARNINGS (LOSS) PER SHARE (in dollars per share)	$ 0.35	$ 1.07	$ (0.14)	$ 1.42
DILUTED EARNINGS (LOSS) PER SHARE (in dollars per share)	$ 0.35	$ 1.07	$ (0.14)	$ 1.42
Weighted average common shares:
Basic (in shares)	43,837	50,522	46,614	50,501
Diluted (in shares)	44,219	50,566	46,614	50,637
COMPREHENSIVE INCOME (LOSS):
Net income (loss)	$ 15,419	$ 53,951	$ (6,652)	$ 71,685
Net unrealized appreciation (depreciation) on marketable securities, net of taxes	1,514	(1,945)	2,994	(1,945)
TOTAL COMPREHENSIVE INCOME (LOSS)	16,933	52,006	(3,658)	69,740
Flying agreements
OPERATING REVENUES:
Total operating revenues	700,394	773,774	1,364,232	1,481,837
Lease, airport services and other
OPERATING REVENUES:
Total operating revenues	$ 25,249	$ 25,311	$ 53,242	$ 52,400