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Stock Option, Restrictive Stock Incentive, And Dividend Reinvestment Plans (Summary Of Assumptions To Estimate The Fair Value Of Stock Options Granted)(Details) - Employee Stock Options [Member]
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Expected dividend yield 1.70% 1.84% 0.42%
Expected weighted-average lives of options granted 6 years 2 months 6 years 1 month 6 years 1 month
Expected weighted-average volatility 33.79% 36.19% 42.40%
Expected volatility range, minimum 24.55% 27.27% 35.80%
Expected volatility range, maximum 61.49% 62.98% 62.21%
Risk-free interest rate 1.96% 1.16% 1.10%