Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net earnings	$ 38,612	$ 39,025
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	21,732	22,426
Stock compensation expense	3,622	3,459
Deferred income taxes	(324)	(179)
Provision for (recovery of) doubtful accounts	666	(50)
Foreign currency transaction loss	74	(137)
Asset impairment charge	114	979
Gain on disposal of assets	(2,717)	(551)
Changes in assets and liabilities
Accounts receivable	563	(7,560)
Inventories	(681)	(9,565)
Prepaid expenses and other current assets	(1,062)	(724)
Accounts payable and accrued expenses	(11,039)	754
Income taxes	(609)	(1,958)
Other	(139)	777
Net cash provided by operating activities	48,812	46,696
Cash flows from investing activities:
Cash paid for acquisition, net of cash acquired	(94,690)	0
Capital expenditures	(14,688)	(7,700)
Proceeds from insurance	2,727	1,590
Proceeds from sale of assets	2	576
Intangible assets acquired	(26)	(296)
Purchase of convertible note	(1,000)	0
Net cash used in investing activities	(107,675)	(5,830)
Cash flows from financing activities:
Proceeds from revolving loan	108,569	210,750
Principal payments on revolving loan	(36,000)	0
Principal payments on long-term debt	0	(219,500)
Principal payments on acquired debt	(12,222)	0
Cash paid for financing costs	0	(1,123)
Proceeds from stock options exercised	1,809	6,578
Dividends paid	(15,135)	(13,428)
Purchase of treasury stock	(727)	(1,223)
Net cash provided by (used in) financing activities	46,294	(17,946)
Effect of exchange rate changes on cash	(25)	(860)
(Decrease) increase in cash and cash equivalents	(12,594)	22,060
Cash and cash equivalents beginning of period	54,268	40,416
Cash and cash equivalents end of period	$ 41,674	$ 62,476