CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
NET CASH USED IN OPERATING ACTIVITIES	$ (1,917)	$ (8,394)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of marketable securities	(87,218)	(120,245)
Sales of marketable securities	120,220	234,872
Proceeds from the sale of equipment	630	110
Acquisition of property and equipment:
Aircraft and rotable spare parts	(14,860)	(16,320)
Deposits on aircraft		(13,200)
Buildings and ground equipment	(35)	(2,303)
Increase in other assets	(13,032)	(8,603)
NET CASH PROVIDED BY INVESTING ACTIVITIES	5,705	74,311
CASH FLOWS FROM FINANCING ACTIVITIES:
Principal payments on long-term debt	(33,675)	(30,897)
Net proceeds from issuance of common stock	2,236	2,201
Purchase of treasury stock	(897)	(19,581)
Payment of cash dividends	(2,032)	(2,238)
NET CASH USED IN FINANCING ACTIVITIES	(34,368)	(50,515)
Increase (decrease) in cash and cash equivalents	(30,580)	15,402
Cash and cash equivalents at beginning of period	129,526	112,338
CASH AND CASH EQUIVALENTS AT END OF PERIOD	98,946	127,740
Cash paid (received) during the period for:
Interest, net of capitalized amounts	15,294	16,312
Income taxes	$ (54)	$ 467