Consolidated Statements of Operations - USD ($) shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
REVENUES	$ 516,916,000	$ 465,955,000	$ 1,512,444,000	$ 1,251,915,000
OPERATING EXPENSES
Salaries, wages and benefits	169,967,000	148,074,000	494,526,000	431,614,000
Fuel	68,620,000	50,176,000	202,080,000	117,210,000
Maintenance, materials and repairs	41,541,000	43,751,000	116,657,000	131,671,000
Depreciation and amortization	83,283,000	77,751,000	246,726,000	224,435,000
Travel	29,865,000	24,928,000	82,544,000	61,833,000
Contracted ground and aviation services	18,278,000	21,620,000	56,762,000	55,217,000
Rent	8,383,000	5,807,000	22,114,000	17,401,000
Landing and ramp	4,210,000	4,027,000	12,873,000	10,162,000
Insurance	2,346,000	3,178,000	7,224,000	9,382,000
Other operating expenses	17,764,000	17,205,000	57,968,000	48,378,000
Operating Expenses	444,257,000	366,195,000	1,299,474,000	1,010,677,000
OPERATING INCOME	72,659,000	99,760,000	212,970,000	241,238,000
OTHER INCOME (EXPENSE)
Interest income	56,000	8,000	80,000	36,000
Non-service component of retiree benefit costs	4,635,000	4,457,000	15,411,000	13,370,000
Write off of Deferred Debt Issuance Cost	0	0	0	(6,505,000)
Non-service component of retiree benefit (costs) gains	(12,167,000)	(14,459,000)	(33,027,000)	(44,002,000)
Net gain (loss) on financial instruments	695,000	(7,378,000)	9,402,000	37,797,000
Other Nonoperating Income (Expense)	(7,735,000)	(18,519,000)	(13,711,000)	(669,000)
EARNINGS FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	64,924,000	81,241,000	199,259,000	240,569,000
INCOME TAX EXPENSE		(18,878,000)	(45,065,000)	(56,047,000)
EARNINGS FROM CONTINUING OPERATIONS	50,188,000	62,363,000	154,194,000	184,522,000
EARNINGS (LOSS) FROM DISCONTINUED OPERATIONS, NET OF TAXES	854,000	2,309,000	1,736,000	2,374,000
NET EARNINGS	$ 51,042,000	$ 64,672,000	$ 155,930,000	$ 186,896,000
BASIC EARNINGS PER SHARE
Basic earnings per share from continuing operations (in dollars per share)	$ 0.68	$ 0.85	$ 2.08	$ 2.75
Discontinued operations (in dollars per share)	0.01	0.03	0.03	0.03
TOTAL BASIC EARNINGS PER SHARE (in dollars per share)	0.69	0.88	2.11	2.78
DILUTED EARNINGS PER SHARE
Diluted earnings per share from continuing operations (in dollars per share)	0.57	0.81	1.76	2.14
Discontinued operations (in dollars per share)	0.01	0.03	0.02	0.03
TOTAL DILUTED NET EARNINGS PER SHARE (in dollars per share)	$ 0.58	$ 0.84	$ 1.78	$ 2.17
WEIGHTED AVERAGE SHARES
Basic (in shares)	73,998	73,721	73,956	67,177
Diluted (in shares)	88,746	76,743	88,980	75,277
Income Tax (Expense) Benefit, Continuing Operations, Government Grants	$ 0	$ (30,322,000)	$ 0	$ (96,626,000)
Accounting Standards Update 2014-09 [Member]
OTHER INCOME (EXPENSE)
INCOME TAX EXPENSE	14,736,000
Significant Reconciling Items [Member]
OTHER INCOME (EXPENSE)
Non-service component of retiree benefit (costs) gains	(510,000)	(371,000)	(1,391,000)	(1,995,000)
Income (Loss) from Equity Method Investments	$ (954,000)	$ (1,147,000)	$ (5,577,000)	$ (1,365,000)