Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 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 and nine months ended September 30, 2013 and 2012 are as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2013		2012		2013		2012
Risk free interest rate	1.5% to 1.7%		0.7% to 0.9%		0.8% to 1.7%		0.2% to 1.2%
Expected term	5.1 to 6.0 years		5.0 to 6.1 years		5.0 to 6.1 years		5.0 to 6.1 years
Expected volatility	82.8% to 83.9%		80.1% to 81.7%		82.8% to 87.9%		80.1% to 82.8%
Expected dividend yield	—	%	—	%	—	%	—	%

Stock-Based Compensation Expense

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

	Three Months Ended September 30,				Nine Months Ended September 30,
	2013		2012		2013		2012
Cost of sales	$	119	$	53	$	227	$	130
Research and development	316		256		782		687
Selling, general and administrative	1,780		1,433		4,570		3,721
Restructuring	—		—		201		—
Total	$	2,215	$	1,742	$	5,780	$	4,538