CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
CURRENT ASSETS:
Cash and cash equivalents	$ 141,760	$ 148,277
Marketable securities	692,509	686,946
Receivables, net	102,772	82,854
Inventories, net	134,382	127,114
Other current assets	43,733	86,705
Total current assets	1,115,156	1,131,896
PROPERTY AND EQUIPMENT:
Aircraft and rotable spares	8,407,450	8,323,107
Deposits on aircraft	77,282	77,282
Buildings and ground equipment	319,512	282,398
Total property and equipment, gross	8,804,244	8,682,787
Less-accumulated depreciation and amortization	(3,369,494)	(3,199,820)
Total property and equipment, net	5,434,750	5,482,967
OTHER ASSETS:
Operating lease right-of-use assets	82,359	86,727
Long-term receivables and other assets	330,174	324,703
Total other assets	412,533	411,430
Total assets	6,962,439	7,026,293
CURRENT LIABILITIES:
Current maturities of long-term debt	497,744	443,869
Accounts payable	479,627	470,251
Accrued salaries, wages and benefits	197,975	194,881
Current maturities of operating lease liabilities	18,805	19,335
Taxes other than income taxes	24,659	26,077
Other current liabilities	105,118	99,879
Total current liabilities	1,323,928	1,254,292
LONG-TERM DEBT, net of current maturities	2,284,375	2,562,183
DEFERRED INCOME TAXES PAYABLE	725,430	687,600
NONCURRENT OPERATING LEASE LIABILITIES	63,554	67,392
OTHER LONG-TERM LIABILITIES	333,972	341,324
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; 83,139,289 and 82,840,372 shares issued as of June 30, 2024, and December 31, 2023, respectively	766,130	754,362
Retained earnings	2,407,087	2,271,211
Treasury stock, at cost, 43,045,566 and 42,615,347 shares as of June 30, 2024, and December 31, 2023, respectively	(941,529)	(912,396)
Accumulated other comprehensive income (loss)	(508)	325
Total stockholders' equity	2,231,180	2,113,502
Total liabilities and stockholders' equity	$ 6,962,439	$ 7,026,293