Stock Plans (Tables)

6 Months Ended

Jun. 30, 2013

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of stock-based compensation expense

Compensation cost for restricted stock, restricted stock units, employee stock options and the ESPP included in cost of revenue; selling, general and administrative expense; and research and development expense is as follows (in thousands):

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2013		2012		2013		2012
Cost of revenue	$	261	$	238	$	534	$	380
Selling, general and administrative	507		411		1,004		1,374
Research and development	178		121		365		302
Total stock-based compensation expense	$	946	$	770	$	1,903	$	2,056

Restricted Stock Awards

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of employee stock purchase plan weighted-average assumptions

The following table summarizes the amount of compensation expense recognized for restricted stock awards for the three and six months endedJune 30, 2013 and 2012 (in thousands):

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2013		2012		2013		2012
Service-based restricted stock	$	621	$	368	$	1,270	$	847
Performance-based restricted stock	25		97		43		160
Total compensation expense recognized for restricted stock awards	$	646	$	465	$	1,313	$	1,007

Schedule of stock-based compensation expense

The Company may determine to grant stock options in the future under the Incentive Plan.

	Three Months Ended			Six Months Ended
	June 30,			June 30,
	2013			2013
Expected dividends	$	—		$	—
Exercise price	$	6.80		6.80
Expected volatility	68.6		%	68.6		%
Average risk-free interest rate	1.1		%	1.1		%
Expected life/term (in years)	4.8			4.8
Fair value per share	$	3.72		$	3.72

Employee Stock [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of stock-based compensation expense

The fair value of the ESPP shares was estimated using the Black-Scholes valuation model for a call and a put option with the following weighted-average assumptions:

	Three Months Ended			Six Months Ended
	June 30,			June 30,
	2012			2012
Expected dividends	$	—		$	—
Exercise price	16.24			16.24
Expected volatility	63		%	63		%
Average risk-free interest rate	0.06		%	0.06		%
Expected life/term (in years)	0.5			0.5
Fair value per share	$	5.26		$	5.26