Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Consolidated Statements of Comprehensive Income [Abstract]
Net Earnings	$ 50,651us-gaap_NetIncomeLoss	$ 40,231us-gaap_NetIncomeLoss	$ 41,584us-gaap_NetIncomeLoss
Other Comprehensive (Loss) Income:
Foreign currency translation adjustments	(10,112)	(2,242)	574
Pension and retiree medical benefits	(5,382)	12,282	(2,534)
Income Taxes:
Foreign currency translation adjustments	13	(15)	(25)
Pension and retiree medical benefits	1,859	(4,663)	889
Total Other Comprehensive Income (Loss), net of tax	(13,622)	5,362	(1,096)
Comprehensive Income	$ 37,029us-gaap_ComprehensiveIncomeNetOfTax	$ 45,593us-gaap_ComprehensiveIncomeNetOfTax	$ 40,488us-gaap_ComprehensiveIncomeNetOfTax

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

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Amount before tax, after 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 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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