CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
CURRENT ASSETS:
Cash and cash equivalents	$ 267,746	$ 133,772
Marketable securities	440,468	556,117
Restricted cash	19,559	19,553
Receivables, net	94,806	130,102
Inventories, net	132,871	113,581
Prepaid aircraft rents	335,379	325,999
Deferred tax assets	160,974	124,320
Other current assets	27,799	30,596
Total current assets	1,479,602	1,434,040
PROPERTY AND EQUIPMENT:
Aircraft and rotable spares	4,049,227	3,997,926
Deposits on aircraft	35,629
Buildings and ground equipment	279,164	274,085
Total property and equipment, gross	4,364,020	4,272,011
Less accumulated depreciation and amortization	(1,699,768)	(1,561,015)
Total property and equipment, net	2,664,252	2,710,996
OTHER ASSETS
Intangible assets, net	15,560	17,248
Other assets	105,980	92,353
Total other assets	121,540	109,601
Total assets	4,265,394	4,254,637
CURRENT LIABILITIES:
Current maturities of long-term debt	174,962	171,454
Accounts payable	231,380	222,671
Accrued salaries, wages and benefits	126,677	121,352
Accrued aircraft rents	8,725	12,745
Taxes other than income taxes	20,761	22,353
Income tax payable	405	1,255
Other current liabilities	41,247	39,595
Total current liabilities	604,157	591,425
OTHER LONG-TERM LIABILITIES	75,544	57,422
LONG-TERM DEBT, net of current maturities	1,349,209	1,470,568
DEFERRED INCOME TAXES PAYABLE	725,613	657,620
DEFERRED AIRCRAFT CREDITS	83,419	90,427
COMMITMENTS AND CONTINGENCIES
STOCKHOLDERS' EQUITY:
Preferred stock, 5,000,000 shares authorized; none issued
Common stock, no par value, 120,000,000 shares authorized; 77,322,304 and 76,713,154 shares issued, respectively	617,701	609,763
Retained earnings	1,191,265	1,147,117
Treasury stock, at cost, 26,095,636 and 25,280,364 shares, respectively	(382,950)	(371,211)
Accumulated other comprehensive income	1,436	1,506
Total stockholders' equity	1,427,452	1,387,175
Total liabilities and stockholders' equity	$ 4,265,394	$ 4,254,637