Condensed Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities:
Net loss	$ (16,415)	$ (27,823)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	30,858	31,565
Amortization of debt discount	1,144	1,567
Amortization of debt issuance costs	1,358	3,837
Share-based compensation	2,772	1,408
Deferred income taxes	(4,685)	(8,931)
Equity in losses of investment	152	123
Loss on disposition of assets, net	39	0
Unrealized gain and ineffectiveness on derivative contracts, net	(1,072)	(4,349)
Changes in operating assets and liabilities:
Accounts receivable, net	36,130	31,522
Other current assets	(4,814)	(2,505)
Income tax receivable	(1,148)	(2,815)
Accounts payable and accrued liabilities	6,697	(21,108)
Other non-current, net	(22,167)	(1,684)
Net cash provided by operating activities	28,849	807
Cash flows from investing activities:
Capital expenditures	(48,000)	(22,869)
Distribution from equity investment	0	1,200
Proceeds from sale of equity investment	0	25,000
Proceeds from sale of assets	0	10,887
Net cash provided by (used in) investing activities	(48,000)	14,218
Cash flows from financing activities:
Repayment of Nordea Q5000 Loan	(8,929)	(8,929)
Repayment of Term Loan	(6,409)	(7,500)
Repayment of MARAD Debt	(3,073)	(2,927)
Debt issuance costs	(54)	(1,211)
Net proceeds from issuance of common stock	219,509	0
Payments related to tax withholding for share-based compensation	(1,306)	(173)
Proceeds from issuance of ESPP shares	144	600
Net cash provided by (used in) financing activities	199,882	(20,140)
Effect of exchange rate changes on cash and cash equivalents	348	(893)
Net increase (decrease) in cash and cash equivalents	181,079	(6,008)
Cash and cash equivalents:
Balance, beginning of year	356,647	494,192
Balance, end of period	$ 537,726	$ 488,184