Consolidated Statements of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 93,344us-gaap_NetIncomeLoss	$ (370)us-gaap_NetIncomeLoss
Other comprehensive income (loss), net of tax:
Changes in pension liability and other post-retirement benefit obligations	2,022	0
Tax effect of changes in pension liability and other post-retirement benefit obligations	(395)	0
Foreign currency translation adjustments	(1,397)	(229)
Other comprehensive income (loss)	230	(229)
Comprehensive income (loss)	$ 93,574us-gaap_ComprehensiveIncomeNetOfTax	$ (599)us-gaap_ComprehensiveIncomeNetOfTax

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature, attributable to parent entity.

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Amount after tax of other comprehensive income (loss) attributable to parent entity.

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Amount before tax, after reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans.

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Amount of tax (expense) benefit, after reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans.

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