Unaudited Condensed Consolidated Statements of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash flows from operating activities:
Net income (loss)	$ (13,371,000)	$ 30,756,000
Adjustments to reconcile net income (loss) to net cash provided by operations:
Depreciation and amortization	37,253,000	37,561,000
Amortization of stock-based compensation	3,649,000	3,790,000
Amortization of deferred financing costs	1,205,000	926,000
Provision for doubtful accounts receivable, net of write-offs	(955,000)	2,174,000
Impairment charge	0	7,459,000
Deferred income tax provision (benefit)	(9,925,000)	138,000
Foreign currency transaction loss	(477,000)	(932,000)
Change in operating assets and liabilities:
Accounts receivable	19,082,000	(28,440,000)
Prepaids and other	(3,510,000)	(3,048,000)
Accounts payable	(9,371,000)	1,053,000
Other accrued liabilities and other	(6,240,000)	(1,956,000)
Net cash provided by operating activities	17,340,000	49,481,000
Cash flows from investing activities:
Purchases of vessels, equipment and other fixed assets	(21,304,000)	(121,631,000)
Release of deposits held in escrow	3,683,000	5,060,000
Proceeds from disposition of vessels and equipment	715,000	0
Net cash used in investing activities	(16,906,000)	(116,571,000)
Cash flows from financing activities:
Proceeds from borrowings under revolving loan facility	28,000,000	50,045,000
Repayment of secured credit facilities	0	(5,000,000)
Cash dividends	0	(13,421,000)
Debt issuance costs	(1,226,000)	0
Proceeds from issuance of stock	528,000	522,000
Net cash provided by financing activities	27,302,000	32,146,000
Effect of exchange rate changes on cash	(131,000)	318,000
Net increase (decrease) in cash and cash equivalents	27,605,000	(34,626,000)
Cash and cash equivalents at beginning of the period	50,785,000	60,566,000
Cash and cash equivalents at end of period	78,390,000	25,940,000
Supplemental cash flow information:
Interest paid, net of interest capitalized	14,773,000	12,387,000
Income taxes paid, net	$ 934,000	$ 2,362,000