Note 2 - Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2015

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan [Table Text Block]

	Three Months Ended March 31,
	2015		2014
Cost of revenue	$	242	$	205
Research and development		2,620		2,005
Selling, general and administrative		6,357		5,388
Total	$	9,219	$	7,598

Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block]

	Time-Based RSUs			Weighted-Average Grant Date Fair Value Per Share		PSUs			Weighted-Average Grant Date Fair Value Per Share		MSUs		Weighted-Average Grant Date Fair Value Per Share		Total			Weighted-Average Grant Date Fair Value Per Share
	(in thousands)					(in thousands)					(in thousands)				(in thousands)
Outstanding at January 1, 2015		589		$	28.48		1,659		$	28.11		1,800	$	23.57		4,048		$	26.14
Granted (1)		217		$	48.92		659		$	48.53		-	$	-		876		$	48.63
Performance adjustment (2)		-		$	-		(192	)	$	45.97		-	$	-		(192	)	$	45.97
Released		(117	)	$	22.84		(403	)	$	24.11		-	$	-		(520	)	$	23.83
Forfeited		(9	)	$	29.52		(17	)	$	23.20		-	$	-		(26	)	$	25.42
Outstanding at March 31, 2015		680		$	35.98		1,706		$	34.13		1,800	$	23.57		4,186		$	29.89

Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]

	Shares			Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term		Aggregate Intrinsic Value
	(in thousands)					(in years)		(in thousands)
Outstanding at January 1, 2015		590		$	15.80		1.2	$	20,039
Options exercised		(74	)	$	17.49
Outstanding at March 31, 2015		516		$	15.56		1.0	$	19,132
Options exercisable at March 31, 2015 and expected to vest		516		$	15.56		1.0	$	19,126
Options exercisable at March 31, 2015		503		$	15.64		0.9	$	18,617

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	Three Months Ended March 31,
	2015			2014
Expected term (years)		0.5			0.5
Expected volatility		35.7	%		33.9	%
Risk-free interest rate		0.1	%		0.1	%
Dividend yield		1.2	%		-