Unaudited Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash flows from operating activities:
Net income (loss)	$ 2,871	$ (2,909)
Adjustments to reconcile net income (loss) from operations to net cash provided by (used in) operations:
Depreciation and amortization	15,170	15,029
Gain on sale of assets		(1,149)
Amortization of stock-based compensation	1,689	1,555
Amortization of deferred financing costs	372	1,769
Loss on extinguishment of debt		686
Provision for doubtful accounts receivable, net of write-offs	(442)	23
Deferred income tax provision	112	97
Foreign currency transaction gain	(598)	(670)
Change in operating assets and liabilities:
Accounts receivable	(9,499)	(286)
Prepaids and other	(1,300)	(3,742)
Accounts payable	(4,354)	5,422
Other accrued liabilities and other	(10,178)	(4,404)
Net cash provided by (used in) operating activities	(6,157)	11,421
Cash flows from investing activities:
Purchases of vessels, equipment and other fixed assets	(45,908)	(35,605)
Release of deposits held in escrow	7,945
Proceeds from disposition of vessels and equipment	638	6,350
Net cash used in investing activities	(37,325)	(29,255)
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)
Borrowings under revolving loan facility, net		974
Cash dividends	(6,604)
Stock repurchases	(12,389)
Debt issuance costs	(1,579)	(8,851)
Debt extinguishment cost		(1,244)
Proceeds from exercise of stock options		698
Proceeds from issuance of stock	234	240
Net cash provided by (used in) financing activities	(20,338)	109,892
Effect of exchange rate changes on cash	(2,267)	1,276
Net increase in cash and cash equivalents	(66,087)	93,334
Cash and cash equivalents at beginning of the period	185,175	128,817
Cash and cash equivalents at end of period	119,088	222,151
Supplemental cash flow information:
Interest paid, net of interest capitalized	13,858	8,251
Income taxes paid, net	$ 977	$ 1,311