CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Net sales	$ 250,694	$ 208,888	$ 710,077	$ 634,522
Cost of goods sold	170,071	147,252	490,417	439,536
Gross profit	80,623	61,636	219,660	194,986
Operating expenses
Selling, general and administrative	38,321	34,669	119,165	98,282
Research and development	17,088	13,745	52,247	40,644
Amortization of acquisition related intangible assets	5,117	1,828	15,379	5,630
Other operating expenses	144	1,421	184	1,556
Total operating expenses	60,670	51,663	186,975	146,112
Income from operations	19,953	9,973	32,685	48,874
Other income (expense)
Interest income	321	153	1,075	695
Interest expense	(3,684)	(781)	(9,880)	(2,602)
Loss on securities carried at fair value		(91)		(145)
Other income (expense)	(959)	974	(1,494)	626
Total other income (expense)	(4,322)	255	(10,299)	(1,426)
Income before income taxes and noncontrolling interest	15,631	10,228	22,386	47,448
Income tax provision	4,097	6,593	5,941	16,179
Net income	11,534	3,635	16,445	31,269
Less net income attributable to noncontrolling interest	(886)	(798)	(1,778)	(2,222)
Net income attributable to common stockholders	$ 10,648	$ 2,837	$ 14,667	$ 29,047
Earnings per share attributable to common stockholders:
Basic	$ 0.22	$ 0.06	$ 0.30	$ 0.60
Diluted	$ 0.21	$ 0.06	$ 0.30	$ 0.59
Number of shares used in earnings per share computation:
Basic	48,814	48,586	48,496	48,114
Diluted	49,922	49,564	49,565	49,351