Condensed Consolidated Statements of Comprehensive Earnings - Unaudited - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net earnings	$ 11,419	$ 11,548
Other comprehensive income:
Changes in fair market value of derivatives, net of tax	78	807
Changes in unrealized pension cost, net of tax	1,022	1,107
Cumulative translation adjustment, net of tax	91	243
Other comprehensive income	1,191	2,157
Comprehensive income	$ 12,610	$ 13,705

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 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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