CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income	$ 34,944	$ 49,317	$ 37,187
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	33,162	26,130	19,559
Inventory step-up amortization	1,975	1,108	1,954
Long-lived asset impairment charge	0	772	0
Deferred income taxes	636	(2,933)	(1,172)
Stock-based compensation	2,081	4,269	4,359
(Income) loss from equity method investment	(132)	28	(69)
Loss on disposition of property, plant and equipment	230	0	0
Changes in operating assets and liabilities:
Accounts receivable	(7,127)	(8,046)	379
Contract assets	(3,828)	0	0
Inventories	(6,001)	(11,116)	500
Taxes receivable	3,151	(1,216)	1,169
Prepaid expenses and other assets	(542)	(784)	(3,355)
Accounts payable	(5,055)	14,315	3,505
Accrued taxes	535	(4,708)	1,244
Accrued payroll and other compensation	(2,352)	1,103	1,770
Deferred revenue	3,801	934	1,072
Benefit plan liabilities	(7,658)	(5,245)	487
Other, net	(3,081)	(992)	1,138
Net cash provided by operating activities	44,739	62,936	69,727
Cash flows from investing activities:
Business acquisitions, net of cash acquired	(269,972)	(323)	(152,242)
Capital expenditures	(31,291)	(27,006)	(25,466)
Proceeds from the sale of property, plant and equipment	298	0	0
Net cash used for investing activities	(300,965)	(27,329)	(177,708)
Cash flows from financing activities:
Proceeds from borrowings	338,000	0	116,600
Debt repayments	(89,862)	(51,762)	(10,328)
Debt issuance costs payments	(538)	0	0
Common stock issued	850	1,323	1,194
Common stock repurchased	(974)	(2,770)	(1,091)
Net cash provided by (used for) financing activities	247,476	(53,209)	106,375
Effect of exchange rate changes on cash	(1,888)	5,543	(2,369)
Decrease in cash and cash equivalents	(10,638)	(12,059)	(3,975)
Cash and cash equivalents at beginning of period	59,875	71,934	75,909
Cash and cash equivalents at end of period	49,237	59,875	71,934
Cash paid during the year for:
Interest	5,960	2,747	787
Income taxes, net	$ 4,606	$ 16,158	$ 15,739