CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
CURRENT ASSETS:
Cash and cash equivalents	$ 418,228	$ 87,206
Marketable securities	403,793	432,966
Income tax receivable	3,557	11,141
Receivables, net	32,890	82,977
Inventories, net	92,350	110,503
Other current assets	26,460	35,553
Total current assets	977,278	760,346
PROPERTY AND EQUIPMENT:
Aircraft and rotable spares	7,274,843	7,078,801
Deposits on aircraft	40,263	48,858
Buildings and ground equipment	243,692	265,398
Total property and equipment, gross	7,558,798	7,393,057
Less-accumulated depreciation and amortization	(2,351,052)	(1,998,376)
Total property and equipment, net	5,207,746	5,394,681
OTHER ASSETS:
Operating lease right-of-use assets	296,439	336,009
Other assets	277,131	166,093
Total other assets	573,570	502,102
Total assets	6,758,594	6,657,129
CURRENT LIABILITIES:
Current maturities of long-term debt	360,288	364,126
Accounts payable	244,047	284,473
Accrued salaries, wages and benefits	113,800	133,856
Current maturities of operating lease liabilities	83,291	94,806
Taxes other than income taxes	33,392	15,004
Other current liabilities	25,086	32,411
Total current liabilities	859,904	924,676
LONG-TERM DEBT, net of current maturities	2,707,769	2,628,989
DEFERRED INCOME TAXES PAYABLE	638,938	623,580
NONCURRENT OPERATING LEASE LIABILITIES	221,839	259,237
OTHER LONG-TERM LIABILITIES	145,044	45,633
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; 82,094,985 and 81,742,937 shares issued, as of September 30, 2020 and December 31, 2019, respectively	703,780	686,806
Retained earnings	2,098,456	2,079,179
Treasury stock, at cost, 31,913,635 and 31,420,179 shares issued, as of September 30, 2020 and December 31, 2019, respectively	(617,136)	(590,971)
Total stockholders' equity	2,185,100	2,175,014
Total liabilities and stockholders' equity	$ 6,758,594	$ 6,657,129