Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Net sales	$ 215,435	$ 180,453
Cost of sales	149,268	125,823
Gross profit	66,167	54,630
Operating expenses:
Selling, general and administrative expenses	40,384	33,536
Research and development expenses	6,223	4,564
Restructuring costs	1,898	1,553
Total operating expenses	48,505	39,653
Income from operations	17,662	14,977
Other non-operating income and expense:
Interest expense, net	1,705	2,896
Other non-operating income, net	(530)	(278)
Loss on extinguishment of convertible debt	1,797
Total other non-operating (income) expense, net	2,972	2,618
Income before income taxes	14,690	12,359
Provision for income taxes	4,364	3,549
Net income	$ 10,326	$ 8,810
Weighted average shares, basic	28,763	25,740
Weighted average shares, diluted	28,897	25,759
Net income per share:
Basic net income	$ 0.36	$ 0.34
Diluted net income	0.36	0.34
Cash dividend declared	$ 0.15	$ 0.15