Nature of Business and Summary of Significant Accounting Policies (Details 4)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Black Scholes options-pricing model, assumptions
Dividend yield
Maximum [Member]
Black Scholes options-pricing model, assumptions
Expected price volatility	83.69%	77.75%	79.02%
Risk-free interest rate	1.02%	1.99%	2.36%
Weighted average expected life in years	6 years	6 years	6 years
Minimum [Member]
Black Scholes options-pricing model, assumptions
Expected price volatility	81.96%	69.05%	73.41%
Risk-free interest rate	0.62%	0.90%	1.17%
Weighted average expected life in years	5 years	5 years	5 years