Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net income (loss), including noncontrolling interests	$ (376,980)	$ 195,550	$ 113,049
Adjustments to reconcile net income (loss), including noncontrolling interests, to net cash provided by operating activities:
Income from discontinued operations, net of tax	0	0	(1,073)
Depreciation and amortization	120,401	109,345	98,535
Non-cash impairment charges	361,409	0	0
Amortization of deferred financing costs	5,664	4,870	5,187
Stock-based compensation expense	6,543	3,133	8,307
Amortization of debt discount	5,957	5,596	5,172
Deferred income taxes	(103,022)	23,154	(24,937)
Excess tax benefit from stock-based compensation	0	(68)	(219)
Equity in losses of investments	124,345	0	0
Gain on disposition of assets, net	(92)	(10,240)	(14,727)
Loss on early extinguishment of debt	0	0	12,100
Unrealized losses and ineffectiveness on derivative contracts, net	18,281	1,320	77
Changes in operating assets and liabilities:
Accounts receivable, net	36,354	43,963	(3,320)
Other current assets	7,956	(6,461)	14,277
Income tax payable	(7,464)	9,088	(56,164)
Accounts payable and accrued liabilities	(63,817)	12,841	(32,045)
Oil and gas asset retirement costs	0	(1,024)	(10,334)
Other non-current, net	(24,730)	(31,582)	(9,024)
Net cash provided by operating activities	110,805	359,485	104,861
Net cash used in discontinued operations	0	0	(30,503)
Net cash provided by operating activities	110,805	359,485	74,358
Cash flows from investing activities:
Capital expenditures	(320,311)	(336,912)	(324,426)
Distributions from equity investments, net of earnings	7,000	7,911	9,295
Proceeds from sale of assets	17,592	13,574	189,054
Acquisition of noncontrolling interests	0	(20,085)	0
Net cash used in investing activities	(295,719)	(335,512)	(126,077)
Net cash provided by discontinued operations	0	0	582,965
Net cash provided by (used in) investing activities	(295,719)	(335,512)	456,888
Cash flows from financing activities:
Early extinguishment of Senior Unsecured Notes	0	0	(281,490)
Borrowings under revolving credit facility	0	0	47,617
Repayment of revolving credit facility	0	0	(147,617)
Repurchase of Convertible Senior Notes due 2025	0	0	(3,487)
Proceeds from Nordea Q5000 Loan	250,000	0	0
Repayment of Nordea Q5000 Loan	(17,857)	0	0
Proceeds from Term Loan	0	0	300,000
Repayment of term loans	(22,500)	(15,000)	(374,681)
Repayment of MARAD borrowings	(5,644)	(5,376)	(5,120)
Deferred financing costs	(1,737)	(3,586)	(10,954)
Distributions to noncontrolling interests	0	(1,018)	(4,097)
Repurchases of common stock	(1,121)	(8,382)	(11,256)
Excess tax benefit from stock-based compensation	0	68	219
Exercise of stock options, net and other	0	0	734
Proceeds from issuance of ESPP shares	3,484	3,223	2,711
Net cash provided by (used in) financing activities	204,625	(30,071)	(487,421)
Effect of exchange rate changes on cash and cash equivalents	(2,011)	4,390	(2,725)
Net increase (decrease) in cash and cash equivalents	17,700	(1,708)	41,100
Cash and cash equivalents:
Balance, beginning of year	476,492	478,200	437,100
Balance, end of year	$ 494,192	$ 476,492	$ 478,200