CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
OPERATING REVENUES:
Total operating revenues	$ 457,493	$ 760,295	$ 1,537,469	$ 2,228,372
OPERATING EXPENSES:
Salaries, wages and benefits	194,516	251,414	613,895	752,768
Depreciation and amortization	121,467	92,795	364,813	272,929
CARES Act payroll support grant	(190,200)		(342,138)
Special items				21,869
Other operating expenses	59,580	59,577	167,170	184,634
Total operating expenses	382,940	613,854	1,400,998	1,841,419
OPERATING INCOME	74,553	146,441	136,471	386,953
OTHER INCOME (EXPENSE):
Interest income	1,403	3,542	5,652	11,081
Interest expense	(30,150)	(31,606)	(91,280)	(96,884)
Other income, net	405	361	1,205	47,367
Total other income (expense), net	(28,342)	(27,703)	(84,423)	(38,436)
INCOME BEFORE INCOME TAXES	46,211	118,738	52,048	348,517
PROVISION FOR INCOME TAXES	12,549	27,399	14,113	80,945
NET INCOME	$ 33,662	$ 91,339	$ 37,935	$ 267,572
BASIC EARNINGS PER SHARE (in dollars per share)	$ 0.67	$ 1.80	$ 0.76	$ 5.24
DILUTED EARNINGS PER SHARE (in dollars per share)	$ 0.66	$ 1.79	$ 0.75	$ 5.19
Weighted average common shares:
Basic (in shares)	50,181	50,746	50,199	51,111
Diluted (in shares)	50,622	51,129	50,445	51,568
COMPREHENSIVE INCOME:
Net income	$ 33,662	$ 91,339	$ 37,935	$ 267,572
Net unrealized depreciation on debt securities, net of taxes	(307)			32
TOTAL COMPREHENSIVE INCOME	33,355	91,339	37,935	267,604
Flying agreements
OPERATING REVENUES:
Total operating revenues	445,048	738,838	1,490,912	2,164,173
Lease, airport services and other
OPERATING REVENUES:
Total operating revenues	12,445	21,457	46,557	64,199
Aircraft maintenance, materials and repairs
OPERATING EXPENSES:
Total operating expenses	150,148	133,521	431,654	376,572
Airport related expenses
OPERATING EXPENSES:
Total operating expenses	18,003	27,808	70,192	89,237
Aircraft rentals
OPERATING EXPENSES:
Total operating expenses	15,785	17,676	49,537	55,840
Aircraft fuel
OPERATING EXPENSES:
Total operating expenses	$ 13,641	$ 31,063	$ 45,875	$ 87,570