CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
NET CASH USED IN OPERATING ACTIVITIES	$ (13,836)	$ (1,917)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of marketable securities	(95,255)	(87,218)
Sales of marketable securities	182,560	120,220
Proceeds from the sale of equipment	90	630
Acquisition of property and equipment:
Aircraft and rotable spare parts	(17,525)	(14,860)
Buildings and ground equipment	(1,664)	(35)
Increase in other assets	(13,825)	(13,032)
NET CASH PROVIDED BY INVESTING ACTIVITIES	54,381	5,705
CASH FLOWS FROM FINANCING ACTIVITIES:
Principal payments on long-term debt	(31,627)	(33,675)
Net proceeds from issuance of common stock	2,638	2,236
Purchase of treasury stock	(196)	(897)
Payment of cash dividends	(2,057)	(2,032)
NET CASH USED IN FINANCING ACTIVITIES	(31,242)	(34,368)
Increase (decrease) in cash and cash equivalents	9,303	(30,580)
Cash and cash equivalents at beginning of period	133,772	129,526
CASH AND CASH EQUIVALENTS AT END OF PERIOD	143,075	98,946
Cash paid (received) during the period for:
Interest, net of capitalized amounts	14,603	15,294
Income taxes	$ 388	$ (54)