Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Cash flows from operating activities:
Net income (loss)	$ 26,289	$ (49,981)
Adjustments to reconcile net income (loss) from operations to net cash provided by operations:
Depreciation and amortization	44,554	42,444
(Gain) loss on sale of assets	10	(5,095)
Impairment charge		97,665
Stock based compensation	4,556	4,275
Deferred financing costs	1,260	1,199
Provision for doubtful accounts receivable, net of write-offs	(133)	174
Deferred income tax benefit	(314)	(4,363)
Foreign currency transaction (gain) loss	2,433	(151)
Change in operating assets and liabilities:
Accounts receivable	(15,541)	(7,799)
Prepaids and other	(383)	(2,765)
Accounts payable	1,040	882
Other accrued liabilities and other	(9,576)	(19,125)
Net cash provided by operating activities	54,195	57,360
Cash flows from investing activities:
Purchases of vessels, equipment and other fixed assets	(15,002)	(65,452)
Proceeds from disposition of vessels and equipment		19,582
Net cash used in investing activities	(15,002)	(45,870)
Cash flows from financing activities:
Proceeds from borrowings	10,000	51,000
Repayments of debt	(35,000)	(66,000)
Debt refinancing cost		(2,000)
Proceeds from exercise of stock options	911	1,069
Proceeds from issuance of stock	521	537
Net cash used in financing activities	(23,568)	(15,394)
Effect of exchange rate changes on cash	146	(234)
Net increase (decrease) in cash and cash equivalents	15,771	(4,138)
Cash and cash equivalents at beginning of the period	97,195	92,079
Cash and cash equivalents at end of the period	112,966	87,941
Supplemental cash flow information:
Interest paid, net of interest capitalized	19,218	15,909
Income taxes paid, net	$ 4,485	$ 4,001