CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
NET CASH USED IN OPERATING ACTIVITIES	$ (34,295)	$ (13,836)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of marketable securities	(53,440)	(95,255)
Sales of marketable securities	92,772	182,560
Proceeds from the sale of equipment		90
Acquisition of property and equipment:
Aircraft and rotable spare parts	(66,728)	(17,525)
Buildings and ground equipment	(3,892)	(1,664)
Increase in other assets	(14,257)	(13,825)
NET CASH (USED IN) PROVIDED BY INVESTING ACTIVITIES	(45,545)	54,381
CASH FLOWS FROM FINANCING ACTIVITIES:
Principal payments on long-term debt	(32,932)	(31,627)
Proceeds from issuance of long-term debt	29,281
Net proceeds from issuance of common stock	1,854	2,638
Tax deficiency from exercise of commons stock	(1,266)
Purchase of treasury stock	(3,076)	(196)
Payment of cash dividends	(2,054)	(2,057)
NET CASH USED IN FINANCING ACTIVITIES	(8,193)	(31,242)
Increase (decrease) in cash and cash equivalents	(88,033)	9,303
Cash and cash equivalents at beginning of period	170,636	133,772
CASH AND CASH EQUIVALENTS AT END OF PERIOD	82,603	143,075
Cash paid (received) during the period for:
Interest, net of capitalized amounts	13,122	14,603
Income taxes	$ 451	$ 388