Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Net sales	$ 223,357	$ 182,674	$ 438,792	$ 363,127
Cost of sales	151,231	124,474	300,499	250,297
Gross profit	72,126	58,200	138,293	112,830
Operating expenses:
Selling, general and administrative expenses	41,619	35,870	82,003	69,406
Research and development expenses	6,160	4,514	12,383	9,078
Restructuring costs	1,198	1,641	3,096	3,194
Total operating expenses	48,977	42,025	97,482	81,678
Income from operations	23,149	16,175	40,811	31,152
Other non-operating income and expense:
Interest expense, net	2,031	2,904	3,736	5,800
Other non-operating income, net	(136)	(205)	(666)	(483)
Loss on extinguishment of convertible debt			1,797
Total other non-operating (income) expense, net	1,895	2,699	4,867	5,317
Income before income taxes	21,254	13,476	35,944	25,835
Provision for income taxes	5,870	4,127	10,234	7,676
Net income	$ 15,384	$ 9,349	$ 25,710	$ 18,159
Weighted average shares, basic	28,978	25,699	28,873	25,699
Weighted average shares, diluted	29,114	25,968	29,042	25,793
Net income per share:
Basic net income	$ 0.53	$ 0.36	$ 0.89	$ 0.71
Diluted net income	0.53	0.36	0.89	0.70
Cash dividend declared	$ 0.17	$ 0.15	$ 0.32	$ 0.30