CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Operating activities:
Net (loss) earnings	$ (5,321)	$ 8,838
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	11,363	10,101
Deferred income taxes	(4,559)	5,892
Loss on asset dispositions	1,073	25
Equity in loss of unconsolidated affiliate	41	487
Loss on debt extinguishment	29,216
Other		(53)
Changes in operating assets and liabilities	(25,691)	4,813
Net cash provided by operating activities	6,122	30,103
Investing activities:
Purchase of property and equipment	(38,746)	(24,936)
Proceeds from asset dispositions	2,994	200
Purchase of short-term investments	(140,551)	(70,608)
Proceeds from sale of short-term investments	84,692	75,025
Refund on deposits on aircraft	3,926
Payments of deposits on aircraft	(6,499)	(419)
Net cash used in investing activities	(94,184)	(20,738)
Financing activities:
Proceeds from issuance of Senior Notes due 2019	500,000
Premium and costs to retire debt early	(26,132)
Repayment of Senior Notes due 2018	(292,571)
Debt Issuance costs	(5,657)
Proceeds from line of credit	95,500	2,400
Payments on line of credit	(174,500)	(10,000)
Repurchase of common stock	(176)	(1,037)
Net cash provided by (used in) financing activities	96,464	(8,637)
Increase in cash	8,402	728
Cash, beginning of period	934	2,849
Cash, end of period	9,336	3,577
Cash paid during the period for:
Interest	11,280	733
Income taxes	13	12
Noncash investing activities:
Other current liabilities and accrued payables related to purchase of property and equipment	$ 24,717	$ 82