Consolidated Statement of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net Income	$ 24,320	$ 6,990
Other comprehensive income
Defined benefit pension and postretirement plans	200	170
Foreign currency translation	2,360	1,800
Derivative instruments	(4,040)	380
Total other comprehensive income (loss)	(1,480)	2,350
Total comprehensive income	$ 22,840	$ 9,340

Statement of Comprehensive Income [Abstract]

No definition available.

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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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Amount, after tax, of reclassification adjustment from accumulated other comprehensive (income) loss for prior service cost (credit) of defined benefit plan.

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- Definition

Amount after tax and reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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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.

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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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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