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Stock-Based Compensation (Schedule Of Share-Based Payment Award, Restricted Stock, Valuation Assumptions) (Details)
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Stock-Based Compensation [Abstract]      
Expected volatility 14.10% 15.60% 17.40%
Expected dividend yield 3.30% 3.70% 3.90%
Risk-free rate 0.80% 0.80% 0.40%