Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
REVENUES	$ 1,734,282	$ 1,570,575	$ 1,452,183
OPERATING EXPENSES
Salaries, wages and benefits	591,280	518,961	433,518
Fuel	173,600	148,383	155,033
Maintenance, materials and repairs	173,364	179,315	170,151
Depreciation and amortization	308,448	278,067	257,532
Travel	86,601	77,382	90,993
Contracted ground and aviation services	75,724	63,564	64,076
Rent	23,695	19,299	16,006
Landing and ramp	14,244	12,468	11,184
Insurance	12,588	9,903	7,342
Transaction fees	0	0	373
Other operating expenses	65,179	64,999	68,978
government grants continuing operations	(111,673)	(47,231)	0
Operating Expenses	1,413,050	1,364,185	1,275,186
OPERATING INCOME	321,232	206,390	176,997
OTHER INCOME (EXPENSE)
Interest income	39	222	370
Non-service component of retiree benefit costs	17,827	12,032	(9,404)
Write off of Deferred Debt Issuance Cost	(6,505)	0	0
Non-service component of retiree benefit (costs) gains	(58,790)	(62,893)	(66,644)
Net gain (loss) on financial instruments	29,979	(100,771)	(12,302)
Other Nonoperating Income (Expense)	(20,027)	(164,997)	(105,425)
EARNINGS FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	301,205	41,393	71,572
INCOME TAX EXPENSE	(72,224)	(16,314)	(11,589)
EARNINGS FROM CONTINUING OPERATIONS	228,980	25,079	59,983
EARNINGS (LOSS) FROM DISCONTINUED OPERATIONS, NET OF TAXES	2,440	7,036	1,219
NET EARNINGS	$ 231,420	$ 32,115	$ 61,202
BASIC EARNINGS PER SHARE
Basic earnings per share from continuing operations (in dollars per share)	$ 3.33	$ 0.42	$ 1.02
Discontinued operations (in dollars per share)	0.03	0.12	0.02
TOTAL BASIC EARNINGS PER SHARE (in dollars per share)	3.36	0.54	1.04
DILUTED EARNINGS PER SHARE
Diluted earnings per share from continuing operations (in dollars per share)	2.80	0.42	0.78
Discontinued operations (in dollars per share)	0.03	0.12	0.01
TOTAL DILUTED NET EARNINGS PER SHARE (in dollars per share)	$ 2.83	$ 0.54	$ 0.79
WEIGHTED AVERAGE SHARES
Basic (in shares)	68,853	59,128	58,899
Diluted (in shares)	76,216	59,931	69,348
Asset Impairment Charges	$ 0	$ 39,075	$ 0