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Stock-Based Compensation (Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions) (Details) (USD $)
3 Months Ended
Mar. 31, 2013
Mar. 31, 2012
Stock-Based Compensation [Abstract]    
Weighted average fair value of grants $ 2.50 $ 2.03
Risk-free interest rate 1.86% 2.03%
Dividend yield 1.76% 1.24%
Expected volatility 23.21% 22.04%
Expected life in months 69 months 68 months