Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net earnings	$ 40,893	$ 38,612
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	25,294	21,732
Stock compensation expense	4,501	3,622
Deferred income taxes	386	(324)
Provision for doubtful accounts	329	666
Foreign currency transaction loss	30	74
Asset impairment charge	1,915	114
Loss/(gain) on disposal of assets	37	(2,717)
Changes in assets and liabilities
Accounts receivable	(4,164)	563
Inventories	2,339	(681)
Prepaid expenses and other current assets	(1,970)	(1,062)
Accounts payable and accrued expenses	(9,191)	(11,039)
Income taxes	7,404	(609)
Other	(623)	(139)
Net cash provided by operating activities	67,180	48,812
Cash flows from investing activities:
Cash paid for acquisition, net of cash acquired	0	(94,690)
Capital expenditures and intangible assets acquired	(13,265)	(14,714)
Proceeds from insurance	0	2,727
Proceeds from sale of assets	22	2
Purchase of convertible note	(350)	(1,000)
Net cash used in investing activities	(13,593)	(107,675)
Cash flows from financing activities:
Proceeds from revolving loan	10,000	108,569
Principal payments on revolving loan	(40,000)	(36,000)
Principal payments on acquired debt	0	(12,222)
Proceeds from stock options exercised	6,802	1,809
Dividends paid	(16,704)	(15,135)
Purchase of treasury stock	(3,025)	(727)
Net cash (used in) provided by financing activities	(42,927)	46,294
Effect of exchange rate changes on cash	75	(25)
Increase (decrease) in cash and cash equivalents	10,735	(12,594)
Cash and cash equivalents beginning of period	65,672	54,268
Cash and cash equivalents end of period	$ 76,407	$ 41,674