Unaudited Condensed Consolidated Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities:
Net income (loss)	$ (198,597,000)	$ 55,100,000
Adjustments to reconcile net income (loss) to net cash provided by operations:
Depreciation and amortization	55,927,000	56,729,000
Gain on sale of assets and other	(784,000)	(6,877,000)
Impairment charges	152,103,000	7,459,000
Amortization of stock-based compensation	5,270,000	5,607,000
Amortization of deferred financing costs	1,799,000	1,396,000
Provision for doubtful accounts receivable, net of write-offs	(960,000)	2,158,000
Deferred income tax provision (benefit)	2,689,000	(1,969,000)
Foreign currency transaction loss	157,000	888,000
Change in operating assets and liabilities:
Accounts receivable	33,281,000	(7,010,000)
Prepaids and other	(2,674,000)	(6,601,000)
Accounts payable	(6,998,000)	966,000
Other accrued liabilities and other	(15,924,000)	(3,891,000)
Net cash provided by operating activities	25,289,000	105,312,000
Cash flows from investing activities:
Purchases of vessels, equipment and other fixed assets	(31,874,000)	(142,523,000)
Release of deposits held in escrow	3,683,000	5,060,000
Proceeds from disposition of vessels and equipment	8,226,000	0
Net cash used in investing activities	(19,965,000)	(122,102,000)
Cash flows from financing activities:
Proceeds from borrowings under revolving loan facility	39,000,000	50,045,000
Repayment of borrowings under revolving loan facility	(60,000,000)	(30,703,000)
Cash dividends	$ 0	(20,007,000)
Stock repurchases		(8,189,000)
Debt issuance costs	$ (2,578,000)	0
Proceeds from issuance of stock	702,000	787,000
Net cash used in financing activities	(22,876,000)	(10,628,000)
Effect of exchange rate changes on cash	(2,061,000)	(485,000)
Net decrease in cash and cash equivalents	(19,613,000)	(27,903,000)
Cash and cash equivalents at beginning of the period	50,785,000	60,566,000
Cash and cash equivalents at end of period	31,172,000	32,663,000
Supplemental cash flow information:
Interest paid, net of interest capitalized	30,169,000	28,603,000
Income taxes paid, net	$ 1,371,000	$ 3,585,000