Consolidated Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net income (loss)	$ 10,657	$ (4,545)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation	4,502	4,866
Amortization	10,749	9,058
Stock-based compensation	2,303	1,955
Deferred income taxes	(736)	(4,266)
Increase in cash flows from changes in assets and liabilities:
Accounts receivable	10,145	10,242
Inventories	(4,615)	(3,374)
Accounts payable	8,006	5,202
Accrued compensation and benefits	(7,052)	(8,665)
Other assets	(9,758)	(8,157)
Other liabilities	821	12,982
Total operating	14,365	19,843
Net cash provided by operating activities	25,022	15,298
Cash flows from investing activities:
Purchases of property, plant and equipment	(3,783)	(2,584)
Net cash used in investing activities	(3,783)	(2,584)
Cash flows from financing activities:
Payments on term loan	(3,281)	(2,188)
Payments on revolving line of credit	(49,000)	(36,000)
Proceeds from revolving line of credit	24,000	38,000
Dividends paid on common stock	(5,592)	(5,566)
Other, net	577	(512)
Net cash used in financing activities	(33,296)	(6,266)
Effect of exchange rate changes on cash and cash equivalents	566	784
Net increase (decrease) in cash and cash equivalents	(11,491)	7,232
Cash and cash equivalents at beginning of period	32,622	27,428
Cash and cash equivalents at end of period	21,131	34,660
Non-cash investing and financing activities:
Contractual obligations from asset acquisition	10,000	0
Dividends payable	$ 5,606	$ 5,573