Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Operating activities:
Net (loss) earnings	$ (1,948)	$ 11,085
Adjustments to reconcile net (loss) earnings to net cash provided by operating activities:
Depreciation	15,316	13,442
Deferred income taxes	(1,198)	7,099
Gain on asset dispositions	(223)	(123)
Other	615	577
Changes in operating assets and liabilities	(6,314)	(4,607)
Net cash provided by operating activities	6,248	27,473
Investing activities:
Purchase of property and equipment	(44,378)	(33,932)
Proceeds from asset dispositions	2,000	1,164
Purchase of short-term investments	(153,812)	(1,004)
Proceeds from sale of short-term investments	212,993
Deposits on aircraft	(8,920)
Net cash provided by (used in) investing activities	7,883	(33,772)
Financing activities:
Proceeds from line of credit	19,065	32,000
Payments on line of credit	(33,950)	(25,518)
Net cash (used in) provided by financing activities	(14,885)	6,482
(Decrease) increase in cash	(754)	183
Cash, beginning of period	3,628	2,501
Cash, end of period	2,874	2,684
Cash paid during the period for:
Interest	15,112	7,422
Income taxes	507	607
Noncash investing activities:
Other current liabilities and accrued payables related to purchase of property and equipment	$ 46,007	$ 21