CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
CURRENT ASSETS:
Cash and cash equivalents	$ 96,071	$ 258,421
Marketable securities	878,608	601,989
Receivables, net	75,963	65,348
Inventories, net	115,142	104,093
Other current assets	51,100	38,742
Total current assets	1,216,884	1,068,593
PROPERTY AND EQUIPMENT:
Aircraft and rotable spares	8,052,327	7,848,100
Deposits on aircraft	91,813	124,964
Buildings and ground equipment	270,802	256,595
Total property and equipment, gross	8,414,942	8,229,659
Less-accumulated depreciation and amortization	(2,854,966)	(2,731,060)
Total property and equipment, net	5,559,976	5,498,599
OTHER ASSETS:
Operating lease right-of-use assets	207,845	238,516
Long-term receivables and other assets	351,942	320,239
Total other assets	559,787	558,755
Total assets	7,336,647	7,125,947
CURRENT LIABILITIES:
Current maturities of long-term debt	424,998	391,798
Accounts payable	437,838	496,333
Accrued salaries, wages and benefits	186,062	150,583
Current maturities of operating lease liabilities	75,609	78,886
Taxes other than income taxes	28,611	28,869
Other current liabilities	45,295	48,152
Total current liabilities	1,198,413	1,194,621
LONG-TERM DEBT, net of current maturities	2,864,483	2,717,420
DEFERRED INCOME TAXES PAYABLE	679,794	663,236
NONCURRENT OPERATING LEASE LIABILITIES	134,597	158,274
OTHER LONG-TERM LIABILITIES	114,329	124,882
COMMITMENTS AND CONTINGENCIES (Note 7)
STOCKHOLDERS' EQUITY:
Preferred stock, 5,000,000 shares authorized; none issued
Common stock, no par value, 120,000,000 shares authorized; 82,514,936 and 82,335,970 shares issued as of June 30, 2022, and December 31, 2021, respectively	731,210	722,310
Retained earnings	2,235,601	2,163,916
Treasury stock, at cost, 31,993,144 and 31,956,047 shares as of June 30, 2022, and December 31, 2021, respectively	(619,835)	(618,712)
Accumulated other comprehensive loss	(1,945)
Total stockholders' equity	2,345,031	2,267,514
Total liabilities and stockholders' equity	$ 7,336,647	$ 7,125,947