Condensed Consolidated Statements of Comprehensive Earnings - Unaudited - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net earnings	$ 3,808	$ 11,419
Other comprehensive (loss) earnings:
Changes in fair market value of derivatives, net of tax	(4,414)	78
Changes in unrealized pension cost, net of tax	1,285	1,022
Cumulative translation adjustment, net of tax	(139)	91
Other comprehensive (loss) earnings	(3,268)	1,191
Comprehensive earnings	$ 540	$ 12,610

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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