Stock Compensation Plans (Tables)

9 Months Ended

Sep. 30, 2013

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

Schedule of Share-based Compensation, Stock Options, Activity

A summary of the combined activity under all of our stock option plans during the nine months endedSeptember 30, 2013 is as follows:

	Shares Subject to Options (in thousands)		Weighted-Average Exercise Price per Share		Weighted-Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
As of December 31, 2012	12,488		$	6.17
Granted	2,381		$	4.03
Exercised	(50	)	$	4.06
Forfeitures and cancellations	(1,079	)	$	5.77
Outstanding at September 30, 2013	13,740		$	5.84	7.0	$	322
Options exercisable at September 30, 2013	8,050		$	6.72	5.9	$	322
Options vested or expected to vest at September 30, 2013	13,004		$	5.93	6.9	$	322

Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity

The following table summarizes activity related to our restricted stock awards and restricted stock units during the nine months endedSeptember 30, 2013 (shares in thousands):

	Number of Shares		Weighted-Average Grant Date Fair Value
Outstanding at December 31, 2012	905		$	4.34
Grants and awards	1,107		$	4.01
Vested and released	(338	)	$	4.27
Forfeitures and cancellations	(157	)	$	3.99
Outstanding at September 30, 2013	1,517		$	4.11

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

Following are the weighted-average underlying assumptions used to determine the fair value of stock option award grants and for stock purchase rights under the ESPP:

	Nine Months Ended
	September 30,
	2013			2012
Stock option grants
Risk-free interest rate	1.2		%	1.7		%
Volatility	94.0		%	94.5		%
Dividend yield	—		%	—		%
Expected life (years)	6.9			7.6
Weighted-average grant date fair value	$	3.19		$	3.70

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

	Nine Months Ended
	September 30,
	2013			2012
ESPP stock purchase rights
Risk-free interest rate	0.08		%	0.14		%
Volatility	60.4		%	68.9		%
Dividend yield	—		%	—		%
Expected life (years)	0.5			0.5
Weighted-average grant date fair value	$	1.09		$	1.15

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs

Total non-cash stock-based compensation expense for all stock awards and purchase rights was recognized in our condensed consolidated statements of operations and comprehensive loss as follows (in thousands):

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2013		2012		2013		2012
Cost of revenues	$	239	$	286	$	767	$	853
Selling and marketing expense	651		1,017		2,215		3,001
Research and development expense	534		847		1,908		2,394
General and administrative expense	867		961		3,072		2,976
	$	2,291	$	3,111	$	7,962	$	9,224