Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2014

Stockholders' Equity Note [Abstract]

Summary of Share Based Award Activity

The following table presents the shares available for grant as of March 31, 2014 (in thousands):

	Shares available for grant
December 31, 2013	4,908
Annual increase in shares available for grant	1,525
Option grants	(870	)
Restricted stock unit grants	(75	)
Restricted stock award grants	(229	)
Performance stock unit grants	(775	)
Restricted stock unit award shares withheld for taxes	123
Options forfeited, cancelled or expired	195
Restricted stock units forfeited or cancelled	196
Performance stock units forfeited or cancelled	358
March 31, 2014	5,356

Schedule of stock options activity

A summary of stock option activity for the three months ended March 31, 2014 is as follows (in thousands, except per share amounts and years):

	Options Outstanding
	Number of Options		Weighted Average Exercise Price per Share		Weighted Average Remaining Contractual Terms (years)	Aggregate Intrinsic Value
December 31, 2013	4,126		$	5.68	5.75	$	87
Grants	870		1.94
Exercises	(62	)	1.01			40
Forfeited/Cancelled	(601	)	6.77
March 31, 2014	4,333		$	4.84	6.72	$	245

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

A summary of RSU activity for the three months ended March 31, 2014 is as follows (in thousands, except per share amounts and years):

	RSUs Outstanding
	Number of RSUs		Weighted Average Grant Date Fair Value Per Share		Weighted Average Remaining Contractual Terms (years)	Aggregate Intrinsic Value
December 31, 2013	2,238				1.10	$	3,133
Grants	75		$	1.97
Shares released	(371	)
Forfeited/Cancelled	(196	)
March 31, 2014	1,746				1.07	$	3,562

Schedule of stock-based compensation expense

The following table presents total stock-based compensation expense by functional areas included in the condensed consolidated statements of operations for the three months ended March 31, 2014 and 2013 (in thousands):

	Three Months Ended March 31,
	2014		2013
Research and development	$	239	$	527
Selling, general and administrative	990		945
Total	$	1,229	$	1,472

The following table presents total stock-based compensation expense by security types included in the condensed consolidated statements of operations for the three months ended March 31, 2014 and 2013 (in thousands):

	Three Months Ended March 31,
	2014		2013
Stock options	$	276	$	610
Restricted stock units	869		734
Performance stock units	84		128
Total	$	1,229	$	1,472

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

The Company used the following assumptions to estimate the fair value of its employee option grants:

	Three Months Ended March 31,
	2014		2013
Weighted-average expected life (years)	6.0		6.0
Weighted-average expected volatility	64	%	65	%
Weighted-average risk free interest rate	1.9	%	1.1	%
Expected dividend yield	0.0	%	0.0	%