Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2014

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

The fair value of each stock option granted during the year was estimated on the date of grant using the Black-Scholes option pricing model with the following weighted average assumptions:



	2014		2013		2012
Expected life (years)	5.3		5.4		5.5
Expected volatility	82.9	%	89.6	%	92.4	%
Expected dividend yield	—		—		—
Risk-free interest rate	1.8	%	1.5	%	0.7	%
Weighted average fair value of options granted during the year	$0.39		$0.34		$0.47

Schedule of Share-based Compensation, Stock Options, Activity

The following table summarizes stock option activity for the year ended December 31, 2014:



				Weighted
			Weighted Average	Average Remaining	Aggregate Intrinsic
	Number of Shares		Exercise Price Per Share	Contractual Life (years)	Value (in thousands)
Outstanding at December 31, 2013	4,150,550		$0.75
Granted	659,700		$0.58
Exercised	(57,300	)	0.52
Expired	(615,300	)	$1.19
Forfeited	(485,450	)	$0.53
Outstanding at December 31, 2014	3,652,200		$0.67	7.8	$117
Exercisable at December 31, 2014	2,005,350		$0.80	7.1	$58