CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
Net sales	$ 236,645	$ 219,453	$ 459,383	$ 425,634
Cost of goods sold	161,828	150,016	320,346	292,284
Gross profit	74,817	69,437	139,037	133,350
Operating expenses
Selling, general and administrative	41,390	31,882	80,844	63,613
Research and development	17,010	13,590	35,159	26,899
Amortization of acquisition related intangible assets	5,131	1,880	10,262	3,802
Other operating expenses	9	87	40	135
Total operating expenses	63,540	47,439	126,305	94,449
Income from operations	11,277	21,998	12,732	38,901
Other income (expense)
Interest income	298	244	754	542
Interest expense	(3,684)	(757)	(6,196)	(1,821)
Loss on securities carried at fair value		(125)		(54)
Other income (expense)	901	(103)	(535)	(348)
Total other income (expense)	(2,485)	(741)	(5,977)	(1,681)
Income before income taxes and noncontrolling interest	8,792	21,257	6,755	37,220
Income tax provision	2,396	5,399	1,844	9,586
Net income	6,396	15,858	4,911	27,634
Less net income attributable to noncontrolling interest	(644)	(780)	(892)	(1,424)
Net income attributable to common stockholders	$ 5,752	$ 15,078	$ 4,019	$ 26,210
Earnings per share attributable to common stockholders:
Basic	$ 0.12	$ 0.31	$ 0.08	$ 0.55
Diluted	$ 0.12	$ 0.31	$ 0.08	$ 0.53
Number of shares used in earnings per share computation:
Basic	48,383	48,076	48,336	47,872
Diluted	49,500	49,250	49,380	49,091