CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ 58,956	$ 51,157	$ (27,335)
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	245,005	251,958	254,182
Stock based compensation expense	4,363	4,693	5,365
Loss (gain) on sale of property and equipment		621	(29)
Undistributed losses (earnings) of other companies	(10,830)	10,199	13,273
Capitalized Brasilia engine overhauls	(29,606)	(25,742)	(17,792)
Adjustment to purchase accounting gain			5,711
Net increase (decrease) in deferred income taxes	38,007	34,800	(21,537)
Changes in operating assets and liabilities:
Decrease (increase) in restricted cash	7,334	(119)	2,341
Decrease (increase) in receivables	18,916	408	(10,665)
Decrease (increase) in income tax receivable	(840)	1,568	1,788
Decrease (increase) in inventories	(24,513)	1,630	(8,639)
Increase in other current assets and prepaid aircraft rents	(31,578)	(39,451)	(28,668)
Decrease in deferred aircraft credits	(8,432)	(7,112)	(8,586)
Increase (decrease) in accounts payable and accrued aircraft rents	17,594	(7,653)	10,161
Increase (decrease) in other current liabilities	5,514	11,867	(7,444)
NET CASH PROVIDED BY OPERATING ACTIVITIES	289,890	288,824	162,126
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of marketable securities	(488,564)	(736,330)	(683,396)
Sales of marketable securities	557,424	677,798	857,031
Proceeds from the sale of property and equipment	293	15,265	193
Proceeds from installment payment of equity shares of TRIP	16,658	8,064
Acquisition of property and equipment:
Aircraft and rotable spare parts	(102,499)	(57,277)	(158,942)
Deposits on aircraft	(40,000)		(13,500)
Buildings and ground equipment	(9,502)	(7,662)	(13,756)
Decrease (increase) in other assets	229	(8,218)	817
NET CASH USED IN INVESTING ACTIVITIES	(65,961)	(108,360)	(11,553)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of long-term debt		44,900	76,454
Principal payments on long-term debt	(171,453)	(218,270)	(159,038)
Return of deposits on aircraft and rotable spare parts			13,900
Net proceeds from issuance of common stock	4,385	6,231	4,446
Purchase of treasury stock	(11,739)	(902)	(60,681)
Payment of cash dividends	(8,258)	(8,177)	(8,466)
NET CASH USED IN FINANCING ACTIVITIES	(187,065)	(176,218)	(133,385)
Increase in cash and cash equivalents	36,864	4,246	17,188
Cash and cash equivalents at beginning of year	133,772	129,526	112,338
CASH AND CASH EQUIVALENTS AT END OF YEAR	170,636	133,772	129,526
Cash paid (received) during the year for:
Interest, net of capitalized amounts	71,323	78,407	81,187
Income taxes	$ 3,678	$ (1,354)	$ (2,198)