CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Operating activities:
Net earnings	$ 8,047	$ 28,354
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	23,819	20,863
Deferred income taxes	2,597	18,905
Loss (gain) on asset dispositions	1,315	(14,676)
Equity in loss of unconsolidated affiliate	106	1,083
Loss on debt extinguishment	29,833
Impairment of assets	0	421
Other	0	(70)
Changes in operating assets and liabilities	(20,421)	2,826
Net cash provided by operating activities	45,296	57,706
Investing activities:
Purchase of property and equipment	(66,887)	(50,004)
Proceeds from asset dispositions	7,170	37,255
Purchase of short-term investments	(233,606)	(246,375)
Proceeds from sale of short-term investments	182,336	220,249
Refund on deposits on aircraft	6,473	3,150
Payments of deposits on aircraft	(6,837)	(571)
Other	(200)
Net cash used in investing activities	(111,551)	(36,296)
Financing activities:
Proceeds from issuance of Senior Notes due 2019	500,000
Premium and costs to retire debt early	(26,749)
Repayment of Senior Notes due 2018	(300,000)
Debt issuance costs	(6,137)
Proceeds from line of credit	95,500	41,965
Payments on line of credit	(174,500)	(52,997)
Repurchase of common stock	(176)	(1,037)
Net cash provided by (used in) financing activities	87,938	(12,069)
Increase in cash	21,683	9,341
Cash, beginning of period	934	2,849
Cash, end of period	22,617	12,190
Cash paid during the period for:
Interest	11,749	14,286
Income taxes	9,731	229
Noncash investing activities:
Other current liabilities and accrued payables related to purchase of property and equipment	$ 94	$ 367