Share-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2013

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

Schedule of Stock Option Activity

The following table summarizes stock option activity for the nine month period ended September 30, 2013:

	Number of Shares		Weighted Average Exercise Price Per Share		Weighted Average remaining Contractual Life (years)	Aggregate Intrinsic Value (in thousands)
Outstanding balance at December 31, 2012	6,429,250		$	1.28
Granted	2,325,000		0.47
Exercised	(60,550	)	0.24
Expired	(1,016,950	)	2.67
Forfeited	(1,371,650	)	0.63
Outstanding balance at September 30, 2013	6,305,100		0.91		7.7	$4
Options exercisable at September 30, 2013	3,526,850		$	1.20	6.3	$4

Schedule of Valuation Assumptions

The fair value of the stock options granted during the three and nine month periods ended September 30, 2013 and 2012 was estimated on the date of grant using the Black-Scholes option pricing model with the following weighted average assumptions:

	Three Months Ended September 30,		Nine Months Ended September 30,
	2013	2012	2013		2012
Expected life (years)	5.4	5.5	5.4		5.5
Expected volatility	89.6%	92.4%	89.6	%	92.4%
Expected dividend yield	—%	—%	—%		—%
Risk-free interest rate	1.5%	0.7%	1.5%		0.7%
Weighted average fair value of options granted during the period	$0.34	$0.47	$0.34		$0.47