Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net earnings	$ 71,155	$ 62,461
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	36,622	38,349
Stock compensation expense	8,809	6,755
Deferred income taxes	(806)	532
Provision for doubtful accounts	105	250
Unrealized (gain)/loss on foreign currency transaction and deferred compensation	(534)	153
Asset impairment charge	0	1,915
(Gain)/Loss on disposal of assets	(996)	57
Changes in assets and liabilities
Accounts receivable	(14,088)	(4,979)
Inventories	(11,736)	6,802
Prepaid expenses and other current assets	(3,793)	(844)
Accounts payable and accrued expenses	30,467	(6,978)
Income taxes	(681)	(1,957)
Other	1,499	24
Net cash provided by operating activities	116,023	102,540
Cash flows from investing activities:
Capital expenditures and intangible assets acquired	(22,391)	(20,552)
Proceeds from insurance and sale of assets	1,272	22
Purchase of convertible note	0	(850)
Net cash used in investing activities	(21,119)	(21,380)
Cash flows from financing activities:
Proceeds from revolving loan	5,000	10,000
Principal payments on revolving loan	(60,000)	(65,000)
Principal payments on finance lease	(118)	(112)
Proceeds from stock options exercised	6,351	8,179
Dividends paid	(18,704)	(16,704)
Purchase of treasury stock	(18,762)	(5,982)
Net cash used in financing activities	(86,233)	(69,619)
Effect of exchange rate changes on cash	(3,229)	1,754
Increase in cash and cash equivalents	5,442	13,295
Cash and cash equivalents beginning of period	84,571	65,672
Cash and cash equivalents end of period	$ 90,013	$ 78,967