Note 2 - Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2016

Notes Tables

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,
	2016		2015
Cost of revenue	$	434	$	242
Research and development		3,698		2,620
Selling, general and administrative		4,847		6,357
Total	$	8,979	$	9,219

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 and MPSUs					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
Outstanding at January 1, 2016		499		$	40.75		1,933				$	38.99		1,800		$	23.57		4,232		$	32.64
Granted		61		$	58.98		1,013		(1	)	$	39.50		-		$	-		1,074		$	40.61
Performance adjustment		-		$	-		(97	)	(2	)	$	42.77		-		$	-		(97	)	$	42.77
Released		(71	)	$	35.11		(421	)			$	29.92		-		$	-		(492	)	$	30.66
Forfeited		(14	)	$	43.08		(125	)			$	36.84		(180	)	$	23.57		(319	)	$	29.63
Outstanding at March 31, 2016		475		$	43.87		2,303				$	40.83		1,620		$	23.57		4,398		$	34.80

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

	Three Months Ended March 31,
	2016			2015
Expected term (years)		0.5			0.5
Expected volatility		29.7	%		35.7	%
Risk-free interest rate		0.4	%		0.1	%
Dividend yield		1.4	%		1.2	%