Stock Plans (Tables)

3 Months Ended

Mar. 31, 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
	March 31,
	2013		2012
Cost of revenue	$	273	$	142
Selling, general and administrative	497		962
Research and development	187		182
Total stock-based compensation expense	$	957	$	1,286

Restricted Stock Awards [Member]

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 months endedMarch 31, 2013 and 2012 (in thousands):

	Three Months Ended
	March 31,
	2013		2012
Service-based restricted stock	$	648	$	479
Performance-based restricted stock	18		63
Total compensation expense recognized for restricted stock awards	$	666	$	542

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:

	For the offering period beginning January 1 and ending June 30
	2012
Expected dividends	$	—
Exercise price	16.24
Expected volatility	63		%
Average risk-free interest rate	0.06		%
Expected life/term (in years)	0.5
Fair value per share	$	5.26