Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue	$ 282,535us-gaap_SalesRevenueNet	$ 238,091us-gaap_SalesRevenueNet	$ 213,813us-gaap_SalesRevenueNet
Cost of revenue	129,917us-gaap_CostOfRevenue	110,190us-gaap_CostOfRevenue	100,665us-gaap_CostOfRevenue
Gross profit	152,618us-gaap_GrossProfit	127,901us-gaap_GrossProfit	113,148us-gaap_GrossProfit
Operating expenses:
Research and development	58,590	49,733	48,796
Selling, general and administrative	66,755	54,624	50,018
Litigation benefit, net	(8,027)us-gaap_LitigationSettlementAmount	(371)us-gaap_LitigationSettlementAmount	(2,945)us-gaap_LitigationSettlementAmount
Total operating expenses	117,318us-gaap_OperatingExpenses	103,986us-gaap_OperatingExpenses	95,869us-gaap_OperatingExpenses
Income from operations	35,300us-gaap_OperatingIncomeLoss	23,915us-gaap_OperatingIncomeLoss	17,279us-gaap_OperatingIncomeLoss
Interest and other income, net	1,092us-gaap_OtherNonoperatingIncomeExpense	92us-gaap_OtherNonoperatingIncomeExpense	611us-gaap_OtherNonoperatingIncomeExpense
Income before income taxes	36,392	24,007	17,890
Income tax provision	897us-gaap_IncomeTaxExpenseBenefit	1,109us-gaap_IncomeTaxExpenseBenefit	2,134us-gaap_IncomeTaxExpenseBenefit
Net income	$ 35,495us-gaap_NetIncomeLoss	$ 22,898us-gaap_NetIncomeLoss	$ 15,756us-gaap_NetIncomeLoss
Net income per share:
Basic (in Dollars per share)	$ 0.92us-gaap_EarningsPerShareBasic	$ 0.61us-gaap_EarningsPerShareBasic	$ 0.45us-gaap_EarningsPerShareBasic
Diluted (in Dollars per share)	$ 0.89us-gaap_EarningsPerShareDiluted	$ 0.59us-gaap_EarningsPerShareDiluted	$ 0.43us-gaap_EarningsPerShareDiluted
Weighted-average shares outstanding:
Basic (in Shares)	38,686	37,387	34,871
Diluted (in Shares)	39,793	38,620	36,247
Cash dividends declared per common share (in Dollars per share)	$ 0.45		$ 1.00

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