CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
CURRENT ASSETS:
Cash and cash equivalents	$ 140,546	$ 133,772
Marketable securities	505,516	556,117
Restricted cash	19,559	19,553
Receivables, net	86,892	130,102
Inventories, net	129,206	113,581
Prepaid aircraft rents	362,990	325,999
Deferred tax assets	168,033	124,320
Other current assets	23,350	30,596
Total current assets	1,436,092	1,434,040
PROPERTY AND EQUIPMENT:
Aircraft and rotable spares	4,029,501	3,997,926
Deposits on aircraft	24,200
Buildings and ground equipment	275,477	274,085
Total property and equipment, gross	4,329,178	4,272,011
Less accumulated depreciation and amortization	(1,651,377)	(1,561,015)
Total property and equipment, net	2,677,801	2,710,996
OTHER ASSETS
Intangible assets, net	16,123	17,248
Other assets	110,054	92,353
Total other assets	126,177	109,601
Total assets	4,240,070	4,254,637
CURRENT LIABILITIES:
Current maturities of long-term debt	173,201	171,454
Accounts payable	217,647	222,671
Accrued salaries, wages and benefits	125,738	121,352
Accrued aircraft rents	11,587	12,745
Taxes other than income taxes	19,166	22,353
Income tax payable	1,480	1,255
Other current liabilities	37,133	39,595
Total current liabilities	585,952	591,425
OTHER LONG-TERM LIABILITIES	59,132	57,422
LONG-TERM DEBT, net of current maturities	1,382,849	1,470,568
DEFERRED INCOME TAXES PAYABLE	715,285	657,620
DEFERRED AIRCRAFT CREDITS	85,629	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; 77,178,934 and 76,713,154 shares issued, respectively	614,703	609,763
Retained earnings	1,166,921	1,147,117
Treasury stock, at cost, 25,295,636 and 25,280,364 shares, respectively	(371,407)	(371,211)
Accumulated other comprehensive income	1,006	1,506
Total stockholders' equity	1,411,223	1,387,175
Total liabilities and stockholders' equity	$ 4,240,070	$ 4,254,637