CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
CURRENT ASSETS:
Cash and cash equivalents	$ 114,433	$ 102,984
Marketable securities	747,916	944,231
Receivables, net	104,706	100,523
Inventories, net	123,572	123,209
Other current assets	92,506	100,334
Total current assets	1,183,133	1,371,281
PROPERTY AND EQUIPMENT:
Aircraft and rotable spares	8,233,312	8,143,614
Deposits on aircraft	23,931	23,931
Buildings and ground equipment	273,425	265,019
Total property and equipment, gross	8,530,668	8,432,564
Less-accumulated depreciation and amortization	(3,039,525)	(2,884,084)
Total property and equipment, net	5,491,143	5,548,480
OTHER ASSETS:
Operating lease right-of-use assets	92,803	151,928
Long-term receivables and other assets	348,695	342,864
Total other assets	441,498	494,792
Total assets	7,115,774	7,414,553
CURRENT LIABILITIES:
Current maturities of long-term debt	442,155	438,502
Accounts payable	457,310	422,001
Accrued salaries, wages and benefits	189,265	186,285
Current maturities of operating lease liabilities	18,715	71,726
Taxes other than income taxes	22,631	20,480
Other current liabilities	35,918	33,549
Total current liabilities	1,165,994	1,172,543
LONG-TERM DEBT, net of current maturities	2,743,804	2,941,772
DEFERRED INCOME TAXES PAYABLE	682,694	687,060
NONCURRENT OPERATING LEASE LIABILITIES	73,894	88,622
OTHER LONG-TERM LIABILITIES	292,149	176,925
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; 82,800,633 and 82,592,830 shares issued as of June 30, 2023, and December 31, 2022, respectively	744,276	734,426
Retained earnings	2,230,217	2,236,869
Treasury stock, at cost, 40,427,758 and 31,994,416 shares as of June 30, 2023, and December 31, 2022, respectively	(816,446)	(619,862)
Accumulated other comprehensive loss	(808)	(3,802)
Total stockholders' equity	2,157,239	2,347,631
Total liabilities and stockholders' equity	$ 7,115,774	$ 7,414,553