Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2012

Summary of Stock-Based Compensation Expense

The following table summarizes stock-based compensation expense (in thousands):

	Year ended December 31,
	2012		2011		2010
Employee stock-based compensation in:
Cost of revenue	$	2,996	$	3,075	$	2,197
Research and development expense		6,405		6,926		5,013
Selling, general and administrative expense		9,525		10,912		8,329
Total employee stock-based compensation recognized in income (loss)		18,926		20,913		15,539
Amount capitalized in inventory		—		—		10
Total stock-based compensation	$	18,926	$	20,913	$	15,549

Valuation Assumptions for Stock Options

The Company estimated the fair value of all employee stock options using a Black-Scholes valuation model with the following weighted average assumptions:

	Employee Stock Options
	2012			2011			2010
Expected term (in years)		4.70			4.75			4.75
Volatility		56	%		55	%		56	%
Risk-free interest rate		0.9	%		1.8	%		2.4	%
Dividend yield		0.0	%		0.0	%		0.0	%

Employee Stock Purchase Plan

The call option and put option were valued using the Black-Scholes option pricing model with the following assumptions:

	Employee Stock Purchase Plan
	2012			2011			2010
Expected term (in years)		0.50			0.50			0.50
Volatility		49	%		45	%		46	%
Risk-free interest rate		0.2	%		0.2	%		0.4	%
Dividend yield		0.0	%		0.0	%		0.0	%