Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2014

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

Assumptions Used to Compute Share-Based Compensation Costs for Stock Options Granted

The assumptions used to compute the share-based compensation costs for the stock options granted during the years ended December 31, 2014, 2013 and 2012, respectively, using the Black-Scholes option pricing model, were as follows:

	Year Ended December 31,
	2014			2013			2012
Weighted average grant-date fair value of stock options	$	0.57		$	0.63		$	0.80
Assumptions
Risk-free interest rate (weighted average)		1.2	%		0.6	%		0.5	%
Expected dividend yield		—			—			—
Weighted average expected life (years)		4			4			4
Volatility (weighted average)		82.9	%		68.1	%		80.0	%
Forfeiture rate		25.5	%		11.4	%		13.7	%

Assumptions Used Estimate Fair Value of Employee Stock Purchase Plans

Following is a schedule of the shares purchased, the fair value per share, and the Black-Scholes model assumptions for each offering period:

	(Ending)
Offering Period Ended	March 31,			September 30,			March 31,			September 30,			March 31,
	2015			2014			2014			2013			2013
Shares purchased for offering period					13,619			13,734			19,490			18,594
Fair value per share	$	0.43		$	0.83		$	0.30		$	0.44		$	0.65
Assumptions
Risk-free interest rate (average)		0.40	%		0.80	%		0.40	%		0.11	%		0.14	%
Expected dividend yield		—			—			—			—			—
Weighted average expected life (years)		0.5			0.5			0.5			0.5			0.5
Volatility (average)		109.0	%		74.0	%		44.0	%		45.0	%		74.0	%

Stock-Based Non-Cash Compensation Expenses

Stock-based non-cash compensation expenses related to stock options, restricted stock grants and the ESPP were recorded in the financial statements as follows (in thousands):

	Year Ended December 31,
	2014		2013		2012
Cost of revenues	$	13	$	20	$	13
Selling and marketing		270		766		865
Research and development		659		809		765
General and administrative		1,437		1,938		2,306
Restructuring expense		1,273		—		—
Total non-cash stock compensation expense	$	3,652	$	3,533	$	3,949

Summary of Outstanding Stock Options and Related Activity

A summary of the Company’s stock options outstanding under the 2005 Plan as of December 31, 2014 and the activity during the years ended herein are as follows (in thousands except per share amounts):

				Weighted Ave.		Aggregate
	Shares			Exercise Price		Intrinsic Value
Outstanding as of December 31, 2011		2,167		$	11.03	$	—
(2,167 options exercisable at a weighted average exercise price of $11.03)
Granted (weighted average fair value of $0.80)		826		$	1.39
Exercised		(32	)	$	0.50
Cancelled		(686	)	$	12.37
Outstanding as of December 31, 2012		2,275		$	7.02	$	—
(1,474 options exercisable at a weighted average exercise price of $10.09)
Granted (weighted average fair value of $0.63)		120		$	1.31
Exercised		—		$	—
Cancelled		(225	)	$	6.52
Outstanding as of December 31, 2013		2,170		$	6.76	$	—
(1,573 options exercisable at a weighted average exercise price of $8.81)
Granted (weighted average fair value of $0.57)		633		$	0.95
Exercised		(4	)	$	1.38
Cancelled		(665	)	$	5.98
Outstanding as of December 31, 2014		2,134		$	5.29	$	—
Exercisable as of December 31, 2014		1,291		$	8.04	$	—
Vested and expected to vest at December 31, 2014		1,963		$	5.66	$	—

Summary of Outstanding Restricted Stock Awards and Related Activity

A summary of the Company’s restricted stock awards outstanding under the 2005 Plan as of December 31, 2014, and the activity during years ended therein, are as follows (in thousands):

	Number			Weighted average
	of shares			grant date fair value
Unvested at December 31, 2011		1,355		$	3.21
Granted		995		$	2.64
Vested		(611	)	$	6.42
Cancelled and forfeited		(420	)	$	8.73
Unvested at December 31, 2012		1,319		$	4.60
Granted		1,495		$	1.70
Vested		(752	)	$	4.43
Cancelled and forfeited		(316	)	$	3.00
Unvested at December 31, 2013		1,746		$	2.48
Granted		1,625		$	1.79
Vested		(1,442	)	$	2.48
Cancelled and forfeited		(204	)	$	1.79
Unvested at December 31, 2014		1,725		$	1.91