CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
CURRENT ASSETS:
Cash and cash equivalents	$ 108,714	$ 129,526
Marketable securities	501,332	497,552
Restricted cash	19,445	19,434
Income tax receivable	285	1,568
Receivables, net	139,261	130,510
Inventories, net	114,076	115,211
Prepaid aircraft rents	329,874	285,737
Deferred tax assets	79,551	69,519
Other current assets	31,217	31,407
Total current assets	1,323,755	1,280,464
PROPERTY AND EQUIPMENT:
Aircraft and rotable spares	3,986,412	3,973,027
Buildings and ground equipment	294,199	291,294
Total property and equipment, gross	4,280,611	4,264,321
Less accumulated depreciation and amortization	(1,483,375)	(1,380,846)
Total property and equipment, net	2,797,236	2,883,475
OTHER ASSETS
Intangible assets, net	18,373	19,497
Other assets	99,446	98,472
Total other assets	117,819	117,969
Total assets	4,238,810	4,281,908
CURRENT LIABILITIES:
Current maturities of long-term debt	205,524	208,398
Accounts payable	231,196	220,784
Accrued salaries, wages and benefits	117,613	112,987
Accrued aircraft rents	18,489	22,285
Taxes other than income taxes	18,215	21,186
Other current liabilities	38,980	38,508
Total current liabilities	630,017	624,148
OTHER LONG-TERM LIABILITIES	48,775	50,194
LONG-TERM DEBT, net of current maturities	1,525,269	1,606,993
DEFERRED INCOME TAXES PAYABLE	589,610	567,874
DEFERRED AIRCRAFT CREDITS	94,509	98,438
COMMITMENTS AND CONTINGENCIES
STOCKHOLDERS' EQUITY:
Preferred stock, 5,000,000 shares authorized; none issued
Common stock, no par value, 120,000,000 shares authorized; 76,224,130 and 75,833,696 shares issued, respectively	603,491	598,985
Retained earnings	1,116,346	1,104,144
Treasury stock, at cost, 25,279,790 and 25,221,481 shares, respectively	(371,206)	(370,309)
Accumulated other comprehensive income	1,999	1,441
Total stockholders' equity	1,350,630	1,334,261
Total liabilities and stockholders' equity	$ 4,238,810	$ 4,281,908