Earnings per Share (Details) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2016 USD ($) $ / shares shares	Jun. 30, 2015 USD ($) $ / shares shares	Jun. 30, 2016 USD ($) $ / shares shares	Jun. 30, 2015 USD ($) $ / shares shares
Earnings per share
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	155,000	590,000	70,000	490,000
Calculation of basic and diluted earnings per share
Net loss \| $	$ (168,681)	$ (57,508)	$ (515,891)	$ (110,566)
Basic weighted-average common shares outstanding	68,102,000	67,483,000	68,090,000	67,473,000
Add: dilutive effect of stock options, unvested RSU's, and contingent PSU's	0	0	0	0
Diluted weighted-average common shares outstanding	68,102,000	67,483,000	68,090,000	67,473,000
Basic net loss per common share \| $ / shares	$ (2.48)	$ (0.85)	$ (7.58)	$ (1.64)
Diluted net loss per common share \| $ / shares	$ (2.48)	$ (0.85)	$ (7.58)	$ (1.64)
Performance Shares [Member]
Earnings per share
Share-based Compensation, Awards Other Than Options, Performance Measurement Period			3 years
Minimum [Member] \| Performance Shares [Member]
Earnings per share
Multiplier Applied to PSU Awards at Settlement			0
Maximum [Member] \| Performance Shares [Member]
Earnings per share
Multiplier Applied to PSU Awards at Settlement			2.00

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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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