Stockholders' Equity (Tables)

9 Months Ended

Sep. 30, 2017

Notes To Financial Statements [Abstract]

Stock-based Compensation Expense

The stock-based compensation related to all of our stock-based awards and employee stock purchases for the three and nine months ended September 30, 2017 and 2016 is as follows (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2017		2016		2017		2016
Cost of net revenues	$	833	$	995	$	2,526	$	2,888
Selling, general and administrative	11,880		10,797		34,814		31,474
Research and development	2,254		1,919		6,684		5,572
Total stock-based compensation	$	14,967	$	13,711	$	44,024	$	39,934

Stock Option Activity

Activity for the nine months ended September 30, 2017 under the stock option plans is set forth below (in thousands, except years and per share amounts):

	Number of Shares Underlying Stock Options		Weighted Average Exercise Price per Share		Weighted  Average Remaining Contractual  Term (in Years)	Aggregate Intrinsic Value
Outstanding as of December 31, 2016	222		$	14.90
Exercised	(110	)	16.19
Cancelled or expired	(4	)	18.16
Outstanding as of September 30, 2017	108		$	13.47	0.90	$	18,711
Vested and expected to vest at September 30, 2017	108		$	13.47	0.90	$	18,711
Exercisable at September 30, 2017	108		$	13.47	0.90	$	18,711

Summary Of Restricted Stock Units

A summary for the nine months ended September 30, 2017 is as follows (in thousands, except years and per share amounts):

	Shares Underlying RSUs		Weighted Average Grant Date Fair Value		Weighted  Remaining Vesting  Period (in years)	Aggregate Intrinsic  Value
Nonvested as of December 31, 2016	1,789		$	58.39
Granted	456		110.40
Vested and released	(785	)	53.61
Forfeited	(71	)	67.22
Nonvested as of September 30, 2017	1,389		77.72		1.34	$	258,838

Summary Of Market-performance Based Restricted Stock Units

The following table summarizes the MSU performance for the nine months ended September 30, 2017 (in thousands, except years):

	Number of Shares Underlying MSUs		Weighted Average Grant Date Fair Value		Weighted Average Remaining Vesting Period (in years)	Aggregate Intrinsic  Value
Nonvested as of December 31, 2016	520		$	60.49
Granted	201		88.80
Vested and released	(283	)	53.11
Forfeited	(10	)	64.50
Nonvested as of September 30, 2017	428		78.53		1.22	$	79,742

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 September 30,						Nine Months Ended September 30,
	2017			2016			2017			2016
Expected term (in years)	1.2			1.2			1.2			1.2
Expected volatility	28.8		%	27.4		%	26.8		%	30.5		%
Risk-free interest rate	1.2		%	0.5		%	1.0		%	0.7		%
Expected dividends	—			—			—			—
Weighted average fair value at grant date	$	47.02		$	24.44		$	31.36		$	22.23