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Stock-Based Compensation (Weighted-Average Assumptions For Option Awards Granted) (Details) (Employee Stock Option [Member])
3 Months Ended9 Months Ended
Sep. 30, 2011
Sep. 30, 2010
Sep. 30, 2011
Sep. 30, 2010
Employee Stock Option [Member]
    
Expected volatility34.80%34.80%34.40%35.50%
Expected term (in years)6.05.65.85.9
Risk-free interest rate1.00%1.70%1.40%2.10%
Expected dividend yield0.00%0.00%0.00%0.00%