Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Cash flows from operating activities:
Net loss	$ (2,909)	$ (1,167)
Adjustments to reconcile net loss from operations to net cash provided by operations:
Depreciation and amortization	15,029	14,675
(Gain) loss on sale of assets	(1,149)	10
Amortization of stock-based compensation	1,555	1,332
Amortization of deferred financing costs	1,769	408
Loss on extinguishment of debt	686
Provision for doubtful accounts receivable, net of write-offs	23	(28)
Deferred income tax provision	97	762
Foreign currency transaction gain	(670)	(124)
Change in operating assets and liabilities:
Accounts receivable	(286)	(2,385)
Prepaids and other	(3,742)	(4,667)
Accounts payable	5,422	2,116
Other accrued liabilities and other	(4,404)	(5,891)
Net cash provided by operating activities	11,421	5,041
Cash flows from investing activities:
Purchases of vessels, equipment and other fixed assets	(35,605)	(1,522)
Proceeds from disposition of vessels and equipment	6,350
Net cash used in investing activities	(29,255)	(1,522)
Cash flows from financing activities:
Proceeds from issue of 6.375% Senior Notes	300,000
Repayment of 7.75% Senior Notes	(80,258)
Repayments of secured credit facility	(101,667)	(8,333)
Borrowings under revolving loan facility, net	974	10,000
Debt issuance costs	(8,851)
Debt extinguishment cost	(1,244)
Proceeds from exercise of stock options	698	911
Proceeds from issuance of stock	240	215
Net cash provided by financing activities	109,892	2,793
Effect of exchange rate changes on cash	1,276	2,009
Net increase in cash and cash equivalents	93,334	8,321
Cash and cash equivalents at beginning of the period	128,817	97,195
Cash and cash equivalents at end of period	222,151	105,516
Supplemental cash flow information:
Interest paid, net of interest capitalized	8,251	8,468
Income taxes paid, net	$ 1,311	$ 888