Condensed Statements of Operations (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Operating revenues:
Revenues	$ 991,968	$ 904,330	$ 2,860,720	$ 2,460,239
Operating expenses:
Aircraft fuel	253,847	258,818	748,489	709,644
Salaries, wages and benefits	224,069	185,043	644,345	527,895
Landing fees and other rents	69,142	54,542	193,502	162,774
Aircraft rent	40,026	42,682	132,330	134,618
Depreciation and amortization	57,712	43,773	163,351	128,764
Distribution	39,160	37,868	115,481	103,496
Maintenance, materials and repairs	36,152	37,778	102,444	99,141
Special charges (credits)	0	(686)	0	88,656
Loss on disposal of assets	13,410	1,069	16,873	6,561
Other operating	133,769	98,318	367,482	283,841
Total operating expenses	867,287	759,205	2,484,297	2,245,390
Operating income	124,681	145,125	376,423	214,849
Other (income) expense:
Interest expense	25,138	21,925	75,375	60,272
Capitalized interest	(3,400)	(2,657)	(8,932)	(7,205)
Interest income	(6,292)	(4,776)	(20,282)	(13,272)
Other expense	222	302	599	623
Special charges, non-operating	0	1,744	0	90,357
Total other (income) expense	15,668	16,538	46,760	130,775
Income before income taxes	109,013	128,587	329,663	84,074
Provision for income taxes	25,549	31,107	75,622	20,262
Net income	$ 83,464	$ 97,480	$ 254,041	$ 63,812
Basic earnings per share	$ 1.22	$ 1.43	$ 3.71	$ 0.94
Diluted earnings per share	$ 1.22	$ 1.42	$ 3.71	$ 0.93
Passenger [Member]
Operating revenues:
Revenues	$ 973,353	$ 887,956	$ 2,805,848	$ 2,413,447
Other [Member]
Operating revenues:
Revenues	$ 18,615	$ 16,374	$ 54,872	$ 46,792