Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation (Schedule Of Weighted Average Assumptions) (Details)

v2.4.0.6
Stock-Based Compensation (Schedule Of Weighted Average Assumptions) (Details) (USD $)
 3 Months Ended 9 Months Ended
Sep. 30, 2012
Y
Sep. 30, 2011
Y
Sep. 30, 2012
Y
Sep. 30, 2011
Y
Stock Option [Member]
        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expected term, years 4.51 4.49 4.78 5.12 [1]
Expected stock price volatility 31.95% 31.21% 32.20% 30.76% [1]
Risk-free interest rate 0.47% 0.95% 0.88% 1.84% [1]
Expected dividend yield 1.63% 1.53% 1.80% 1.31% [1]
Weighted average grant date fair value (in dollars per share) $ 12.37 $ 13.39 $ 11.57 $ 16.09 [1]
Stock options granted (in shares)     358,169 340,973
Simplified Method [Member]
        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock options granted (in shares)       53,720
Vesting period     fifth anniversary of the grant date  
[1] For the nine months ended September 30, 2011, the Company granted two stock option grants totaling 53,720 shares that vest 100% on the fifth anniversary of the grant date. Because the Company did not have sufficient historical exercise data to provide a reasonable basis for estimating the expected term for these grants, the Company utilized the simplified method in developing an estimate of the expected term of these options.