Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2015

Stock-based Compensation Expense

The stock-based compensation related to all of our stock-based awards and employee stock purchases for the three months ended March 31, 2015 and 2014 is as follows (in thousands):

	Three Months Ended March 31,
	2015		2014
Cost of net revenues	$	978	$	844
Selling, general and administrative	8,771		6,717
Research and development	1,899		1,571
Total stock-based compensation	$	11,648	$	9,132

Stock Option Activity

Activity for the three months ended March 31, 2015 under the stock option plans is set forth below (in thousands, except years and per share amounts):

	Stock Options Number of Shares Underlying Stock Options		Weighted Average Exercise Price per Share		Weighted  Average Remaining Contractual  Term	Aggregate Intrinsic Value
					(in years )
Outstanding as of December 31, 2014	668		$	15.57
Granted	—		—
Exercised	(28	)	11.19
Cancelled or expired	—		—
Outstanding as of March 31, 2015	640		$	15.76	2.66	$	24,324
Vested and expected to vest at March 31, 2015	640		$	15.76	2.66	$	24,324
Exercisable at March 31, 2015	638		$	15.74	2.66	$	24,268

^[1]

Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions

The fair value of the option component of the 2010 Purchase Plan shares was estimated at the grant date using the Black-Scholes option pricing model with the following weighted average assumptions:

	Three Months Ended March 31,
	2015			2014
Expected term (in years)	1.2			1.2
Expected volatility	31.9		%	42.3		%
Risk-free interest rate	0.26		%	0.20		%
Expected dividends	—			—
Weighted average fair value at grant date	$	15.98		$	17.97

Restricted Stock Units (RSUs)

Summary Of Nonvested Shares

A summary of the RSU activity for the three months ended March 31, 2015 is as follows (in thousands, except years):

	Number of Shares Underlying RSU		Weighted Average Grant Date Fair Value		Weighted  Remaining Contractual  Period	Aggregate Intrinsic  Value
					(in years)
Nonvested as of December 31, 2014	2,124		$	42.08
Granted	621		56.74
Vested and released	(498	)	35.76
Forfeited	(30	)	43.30
Nonvested as of March 31, 2015	2,217		$	47.59	1.71	$	119,242

Market Performance Based Restricted Stock Units

Summary Of Nonvested Shares

The following table summarizes the MSU activity for the three months ended March 31, 2015 (in thousands, except years):

	Number of Shares Underlying MSU		Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Period	Aggregate Intrinsic  Value
					(in years )
Nonvested as of December 31, 2014	498		$	42.00
Granted	178		56.75
Vested and released	(157	)	29.45
Nonvested as of March 31, 2015	519		$	48.08	1.81	$	27,931

[1] There were no stock options granted during the three months ended March 31, 2015 and 2014.