Stock Based Compensation (Tables)

3 Months Ended

Mar. 31, 2013

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Assumptions for Option Grants Issued

The company uses the Black-Scholes option-pricing model to determine the fair value of all its option grants. For options granted during the three months ended March 31, 2013, the following assumptions were used:

	For the Three Months Ended March 31, 2013			For the Three Months Ended March 31, 2012
Risk free interest rate		1.12	%		1.06	%
Volatility		77.49	%		75.69	%
Expected lives (years)		6.25			6.10
Expected dividend yield		0.00	%		0.00	%

Stock Option Activity

The following table summarizes option activity of the company:

	Total Number of Shares			Weighted Average Exercise Price		Aggregate Intrinsic Value
Outstanding at January 1, 2013		7,672,384		$	2.54	$	—
Granted		2,073,000			1.71		808,470
Exercised		—			—		—
Cancelled		(393,101	)		5.00		24,600
Outstanding at March 31, 2013		9,350,283		$	2.26	$	5,653,370
Options exercisable at March 31, 2013		5,571,345		$	2.79	$	3,190,725