CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
CURRENT ASSETS:
Cash and cash equivalents	$ 170,636	$ 133,772
Marketable securities	487,239	556,117
Restricted cash	12,219	19,553
Income tax receivable	840
Receivables, net	111,186	130,102
Inventories, net	138,094	113,581
Prepaid aircraft rents	360,781	325,999
Deferred tax assets	156,050	124,320
Other current assets	27,392	30,596
Total current assets	1,464,437	1,434,040
PROPERTY AND EQUIPMENT:
Aircraft and rotable spares	4,080,886	3,997,926
Deposits on aircraft	40,000
Buildings and ground equipment	279,965	274,085
Total property and equipment, gross	4,400,851	4,272,011
Less-accumulated depreciation and amortization	(1,749,058)	(1,561,015)
Total property and equipment, net	2,651,793	2,710,996
OTHER ASSETS
Intangible assets, net	14,998	17,248
Other assets	101,991	92,353
Total other assets	116,989	109,601
Total assets	4,233,219	4,254,637
CURRENT LIABILITIES:
Current maturities of long-term debt	177,389	171,454
Accounts payable	245,518	222,671
Accrued salaries, wages and benefits	133,002	121,352
Accrued aircraft rents	7,492	12,745
Taxes other than income taxes	19,626	22,353
Income tax payable		1,255
Other current liabilities	37,437	39,595
Total current liabilities	620,464	591,425
OTHER LONG TERM LIABILITIES	76,305	57,422
LONG TERM DEBT, net of current maturities	1,293,179	1,470,568
DEFERRED INCOME TAXES PAYABLE	727,358	657,620
DEFERRED AIRCRAFT CREDITS	80,974	90,427
COMMITMENTS AND CONTINGENCIES (Note 6)
STOCKHOLDERS' EQUITY:
Preferred stock, 5,000,000 shares authorized; none issued
Common stock, no par value, 120,000,000 shares authorized; 77,325,702 and 76,713,154 shares issued, respectively	618,511	609,763
Retained earnings	1,197,819	1,147,117
Treasury stock, at cost, 26,095,636 and 25,280,364 shares, respectively	(382,950)	(371,211)
Accumulated other comprehensive income (Note 1)	1,559	1,506
Total stockholders' equity	1,434,939	1,387,175
Total liabilities and stockholders' equity	$ 4,233,219	$ 4,254,637