Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating activities:
Net earnings	$ 18,057	$ 4,852	$ 7,117
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	41,495	31,298	28,081
Deferred income taxes	15,620	3,949	8,579
Loss in equity of unconsolidated affiliate	863
Gain (loss) on asset dispositions	317	302	(239)
Loss on debt restructuring			9,521
Other	(115)	1,046	1,124
Changes in operating assets and liabilities:
Accounts receivable	(41,567)	(9,637)	4,744
Inventories of spare parts	(8,831)	2,093	2,165
Income taxes receivable	(1,267)	212	182
Other assets	(81,199)	4,330	3,753
Accounts payable and accrued liabilities	99,876	(7,288)	13,106
Other long-term liabilities	7,301	(805)	(1,276)
Net cash provided by operating activities	50,550	30,352	76,857
Investing activities:
Purchase of property and equipment	(128,475)	(91,028)	(98,230)
Proceeds from asset dispositions	11,302	6,852	1,171
Purchase of short-term investments	(216,265)	(234,631)	(450,188)
Proceeds from sale of short-term investments	249,041	282,743	375,517
Payments of deposits on aircraft	(8,717)	(13,798)	(3,780)
Refund of deposits on aircraft	2,500	6,000
Loan to unconsolidated affiliate	(975)
Other investments	(50)
Net cash used in investing activities	(91,639)	(43,862)	(175,510)
Financing activities:
Proceeds from issuance of Senior Notes due 2018			300,000
Premium and costs to retire debt early			(7,667)
Repayment of Senior Notes due 2013			(200,000)
Debt issuance costs			(5,322)
Repurchase of common stock	(1,861)
Proceeds from line of credit	127,323	73,865	59,287
Payments on line of credit	(86,615)	(58,892)	(46,518)
Net cash provided by financing activities	38,847	14,973	99,780
(Decrease) increase in cash	(2,242)	1,463	1,127
Cash, beginning of year	5,091	3,628	2,501
Cash, end of year	2,849	5,091	3,628
Cash paid during the period for:
Interest	28,775	28,431	22,088
Income Taxes	237	212	209
Accrued payables related to purchases of property and equipment	$ 101	$ 160	$ 352