Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
REVENUES	$ 409,872	$ 377,794	$ 785,960	$ 767,071
OPERATING EXPENSES
Salaries, wages and benefits	141,524	119,503	283,540	245,034
Fuel	36,592	36,787	67,034	80,586
Maintenance, materials and repairs	45,913	43,704	87,920	85,381
Depreciation and amortization	75,633	68,291	146,684	137,633
Travel	18,501	17,315	36,905	38,972
Contracted ground and aviation services	18,794	13,546	33,597	27,895
Rent	5,726	5,198	11,594	8,684
Landing and ramp	3,026	2,772	6,135	5,517
Insurance	3,068	2,508	6,204	4,176
Other operating expenses	14,750	15,738	31,173	30,954
government grants continuing operations	(38,274)	(9,821)	(66,304)	(9,821)
Operating Expenses	325,253	354,616	644,482	694,086
OPERATING INCOME	84,619	23,178	141,478	72,985
OTHER INCOME (EXPENSE)
Interest income	9	12	28	124
Non-service component of retiree benefit costs	4,456	2,898	8,913	5,796
Write off of Deferred Debt Issuance Cost	(6,505)	0	(6,505)	0
Non-service component of retiree benefit gains	(15,021)	(16,045)	(29,543)	(32,368)
Net gain (loss) on financial instruments	35,703	(109,723)	45,175	(2,679)
Other Nonoperating Income (Expense)	19,607	(129,371)	17,850	(38,404)
EARNINGS (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	104,226	(106,193)	159,328	34,581
INCOME TAX BENEFIT (EXPENSE)		1,031	(37,169)	(6,010)
EARNINGS (LOSS) FROM CONTINUING OPERATIONS	79,869	(105,162)	122,159	28,571
EARNINGS (LOSS) FROM DISCONTINUED OPERATIONS, NET OF TAXES	65	236	65	4,008
NET EARNINGS (LOSS)	$ 79,934	$ (104,926)	$ 122,224	$ 32,579
BASIC EARNINGS PER SHARE
Basic earnings per share from continuing operations (in dollars per share)	$ 1.17	$ (1.78)	$ 1.91	$ 0.48
Discontinued operations (in dollars per share)	0	0.01	0	0.07
TOTAL BASIC EARNINGS PER SHARE (in dollars per share)	1.17	(1.77)	1.91	0.55
DILUTED EARNINGS PER SHARE
Diluted earnings per share from continuing operations (in dollars per share)	0.74	(1.78)	1.23	0.14
Discontinued operations (in dollars per share)	0	0.01	0	0.05
TOTAL DILUTED NET EARNINGS PER SHARE (in dollars per share)	$ 0.74	$ (1.77)	$ 1.23	$ 0.19
WEIGHTED AVERAGE SHARES
Basic (in shares)	68,206	59,130	63,851	59,085
Diluted (in shares)	72,964	59,130	73,849	68,104
Asset Impairment Charges	$ 0	$ 39,075	$ 0	$ 39,075
Significant Reconciling Items [Member]
OTHER INCOME (EXPENSE)
Non-service component of retiree benefit gains	(870)	(681)	(1,624)	(1,336)
Loss from non-consolidated affiliates	$ 965	$ (6,513)	$ (218)	$ (9,277)