Annual report pursuant to Section 13 and 15(d)

Summary Of Significant Accounting Policies (Schedule Of Weighted Average Fair Value Of Options Granted) (Details)

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Summary Of Significant Accounting Policies (Schedule Of Weighted Average Fair Value Of Options Granted) (Details) (USD $)
12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Summary Of Significant Accounting Policies [Abstract]      
Weighted Average, Expected life (years) 4.50    
Range, Expected life (years) 4.50    
Weighted Average, Risk free interest rate 1.85%    
Risk free interest rate, range 1.85%    
Weighted Average, Expected Volatility 42.22%    
Expected volatility, range 42.22%    
Weighted Average, Expected dividend yield 4.46%    
Expected dividend yield, minimum 4.40%    
Expected dividend yield, maximum 4.50%    
Weighted Average, Fair value $ 10.09 $ 8.34 $ 2.73
Fair value, minimum $ 9.95    
Fair value, maximum $ 10.29