Unaudited Condensed Consolidated Statements of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities:
Net loss	$ (138,762,000)	$ (13,371,000)
Adjustments to reconcile net loss to net cash provided by operations:
Depreciation and amortization	30,950,000	37,253,000
Amortization of stock-based compensation	2,731,000	3,649,000
Amortization of deferred financing costs	2,127,000	1,205,000
Provision for doubtful accounts receivable, net of write-offs	23,000	(955,000)
Impairment charges	162,808,000
Loss on sale of assets	5,918,000
Gain on extinguishment of debt	(35,912,000)
Deferred income tax benefit	(38,600,000)	(9,925,000)
Foreign currency transaction (gain) loss	1,066,000	(477,000)
Change in operating assets and liabilities:
Accounts receivable	11,306,000	19,082,000
Prepaids and other	406,000	(3,510,000)
Accounts payable	294,000	(9,371,000)
Other accrued liabilities and other	(8,638,000)	(6,240,000)
Net cash (used in) provided by operating activities	(4,283,000)	17,340,000
Cash flows from investing activities:
Purchases of vessels, equipment and other fixed assets	(13,638,000)	(21,304,000)
Release of deposits held in escrow		3,683,000
Proceeds from disposition of vessels and equipment	1,429,000	715,000
Net cash used in investing activities	(12,209,000)	(16,906,000)
Cash flows from financing activities:
Proceeds from borrowings under revolving loan facility	39,194,000	28,000,000
Repayment of secured credit facilities	(33,448,000)
Debt issuance costs	(831,000)	(1,226,000)
Proceeds from issuance of stock	227,000	528,000
Net cash provided by financing activities	5,142,000	27,302,000
Effect of exchange rate changes on cash	58,000	(131,000)
Net (decrease) increase in cash and cash equivalents	(11,292,000)	27,605,000
Cash and cash equivalents at beginning of period	21,939,000	50,785,000
Cash and cash equivalents at end of period	10,647,000	78,390,000
Supplemental cash flow information:
Interest paid, net of interest capitalized	16,073,000	14,773,000
Income taxes paid, net	$ 1,691,000	$ 934,000