Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2014

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 six months ended June 30, 2014 and 2013 are as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2014		2013		2014	2013
Risk free interest rate	1.6% to 1.9%		1.2	%	1.6% to 2.0%	0.8% to 1.2%
Expected term	5.1 to 6.1 years		5.1 to 6.0 years		5.1 to 6.1 years	5.0 to 6.1 years
Expected volatility	84.2% to 84.7%		84.5% to 85.6%		84.2% to 84.9%	84.5% to 87.9%
Expected dividend yield	—	%	—	%	—%	—%

Stock-Based Compensation Expense

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

	Three Months Ended June 30,				Six Months Ended June 30,
	2014		2013		2014		2013
Cost of goods sold	$	141	$	63	$	268	$	108
Research and development	364		250		721		466
Selling, general and administrative	2,280		1,465		4,303		2,790
Restructuring	—		201		—		201
Total	$	2,785	$	1,979	$	5,292	$	3,565