Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net earnings	$ 59,288	$ 58,239
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	33,485	33,460
Stock compensation expense	5,717	5,208
Deferred income taxes	(198)	(140)
Provision for (recovery of) doubtful accounts	896	(12)
Foreign currency transaction loss	21	(134)
Asset impairment charge	114	1,671
Gain on disposal of assets	(3,220)	(3,093)
Changes in assets and liabilities
Accounts receivable	8,340	(9,226)
Inventories	(6,017)	(10,538)
Prepaid expenses and other current assets	(784)	1,315
Accounts payable and accrued expenses	(145)	5,426
Income taxes	(5,955)	(3,903)
Other	(48)	912
Net cash provided by operating activities	91,494	79,185
Cash flows from investing activities:
Cash paid for acquisition, net of cash acquired	(94,690)	(17,399)
Capital expenditures and intangible assets acquired	(21,669)	(13,691)
Proceeds from insurance	2,727	4,165
Proceeds from sales of business and assets	11,523	576
Purchase of convertible note	(1,000)	0
Net cash used in investing activities	(103,109)	(26,349)
Cash flows from financing activities:
Proceeds from revolving loan	123,569	210,750
Principal payments on revolving loan	(61,000)	(32,750)
Principal payments on long-term debt	0	(219,500)
Principal payments on acquired debt	(12,222)	(19)
Cash paid for financing costs	0	(1,374)
Proceeds from stock options exercised	3,734	8,133
Dividends paid	(15,135)	(13,428)
Purchase of treasury stock	(21,321)	(1,223)
Net cash provided by (used in) financing activities	17,625	(49,411)
Effect of exchange rate changes on cash	(874)	(1,170)
Increase in cash and cash equivalents	5,136	2,255
Cash and cash equivalents beginning of period	54,268	40,416
Cash and cash equivalents end of period	$ 59,404	$ 42,671