Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2013

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

Assumptions used in the Black-Scholes Option-Pricing Model

The assumptions used in the Black-Scholes option-pricing model for the three months ended March 31, 2013 and 2012 are as follows:

	Three Months Ended March 31,
	2013		2012
Risk free interest rate	0.8% to 1.1%		0.2% to 1.2%
Expected term	5.0 to 6.1 years		5.0 to 6.1 years
Expected volatility	86.8% to 87.9%		80.6	%
Expected dividend yield	—	%	—	%

Stock-Based Compensation Expense

The Company recognized stock-based compensation expense as follows (in thousands):

	Three Months Ended March 31,
	2013		2012
Cost of sales	$	45	$	29
Research and development	216		195
Selling, general and administrative	1,325		1,032
Total	$	1,586	$	1,256