Summary Of Operations And Significant Accounting Policies (Weighted Average Assumptions Of Fair Value Options Using Black-Scholes Option-Pricing Model) (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Summary Of Operations And Significant Accounting Policies [Abstract]
Dividend yield	0.00%	0.00%	0.00%
Risk-free interest rate, minimum	0.60%	0.90%	2.60%
Risk-free interest rate, maximum	0.90%	3.70%	3.80%
Expected life (in years)	5 years	5 years	5 years
Historical volatility, minimum	59.30%	60.10%	60.30%
Historical volatility, maximum	60.80%	61.50%	61.90%