CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 49,317	$ 37,187	$ 46,259
Adjustments to reconcile net income to net cash provided by operating activities:
Gain on sale of business	0	0	(18,647)
Depreciation and amortization	26,130	19,559	17,275
Inventory step-up amortization	1,108	1,954	0
Long-lived asset impairment charges	772	0	1,354
Deferred income taxes	(2,933)	(1,172)	3,585
Stock-based compensation	4,269	4,359	2,827
Income (loss) from equity method investment	28	(69)	0
Changes in assets and liabilities:
Accounts receivable	(8,046)	379	(2,749)
Inventories	(11,116)	500	479
Taxes receivable	1,216	(1,169)	(276)
Prepaid expenses and other assets	(784)	(3,355)	(1,337)
Accounts payable	14,315	3,505	(4,886)
Accrued taxes	(4,708)	1,244	(198)
Accrued payroll and other compensation	1,103	1,770	(3,416)
Benefit plan liabilities	(5,245)	487	(4,778)
Other, net	(58)	2,210	66
Net cash provided by operating activities	62,936	69,727	36,110
Cash flows from investing activities:
Business acquisitions, net of cash acquired	(323)	(152,242)	0
Capital expenditures	(27,006)	(25,466)	(20,645)
Proceeds from sale of business, net	0	0	28,550
Net cash (used for) provided by investing activities	(27,329)	(177,708)	7,905
Cash flows from financing activities:
Proceeds from borrowings	0	116,600	0
Debt repayments	(51,762)	(10,328)	(20,571)
Common stock issued	1,323	1,194	1,521
Common stock repurchased	(2,770)	(1,091)	(8,701)
Excess tax benefit on stock awards	0	0	1,044
Net cash (used for) provided by financing activities	(53,209)	106,375	(26,707)
Effect of exchange rate changes on cash	5,543	(2,369)	(3,450)
(Decrease) increase in cash and cash equivalents	(12,059)	(3,975)	13,858
Cash and cash equivalents at beginning of period	71,934	75,909	62,051
Cash and cash equivalents at end of period	59,875	71,934	75,909
Cash paid during the year for:
Interest	2,747	787	632
Income taxes, net	$ 16,158	$ 15,739	$ 20,180