CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
CURRENT ASSETS:
Cash and cash equivalents	$ 148,277	$ 102,984
Marketable securities	686,946	944,231
Receivables, net	82,854	100,523
Inventories, net	127,114	123,209
Other current assets	86,705	100,334
Total current assets	1,131,896	1,371,281
PROPERTY AND EQUIPMENT:
Aircraft and rotable spares	8,323,107	8,143,614
Deposits on aircraft	77,282	23,931
Buildings and ground equipment	282,398	265,019
Total property and equipment, gross	8,682,787	8,432,564
Less-accumulated depreciation and amortization	(3,199,820)	(2,884,084)
Total property and equipment, net	5,482,967	5,548,480
OTHER ASSETS:
Operating lease right-of-use assets	86,727	151,928
Long-term receivables and other assets	324,703	342,864
Total other assets	411,430	494,792
Total assets	7,026,293	7,414,553
CURRENT LIABILITIES:
Current maturities of long-term debt	443,869	438,502
Accounts payable	470,251	422,001
Accrued salaries, wages and benefits	194,881	186,285
Current maturities of operating lease liabilities	19,335	71,726
Taxes other than income taxes	26,077	20,480
Other current liabilities	99,879	33,549
Total current liabilities	1,254,292	1,172,543
LONG-TERM DEBT, net of current maturities	2,562,183	2,941,772
DEFERRED INCOME TAXES PAYABLE	687,600	687,060
NONCURRENT OPERATING LEASE LIABILITIES	67,392	88,622
OTHER LONG-TERM LIABILITIES	341,324	176,925
COMMITMENTS AND CONTINGENCIES (Note 5)
STOCKHOLDERS' EQUITY:
Preferred stock, 5,000,000 shares authorized; none issued
Common stock, no par value, 120,000,000 shares authorized; 82,840,372 and 82,592,830 shares issued as of December 31, 2023, and December 31, 2022, respectively	754,362	734,426
Retained earnings	2,271,211	2,236,869
Treasury stock, at cost, 42,615,347 and 31,994,416 shares as of December 31, 2023, and December 31, 2022, respectively	(912,396)	(619,862)
Accumulated other comprehensive income (loss)	325	(3,802)
Total stockholders' equity	2,113,502	2,347,631
Total liabilities and stockholders' equity	$ 7,026,293	$ 7,414,553