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 6 Months Ended
Jun. 30, 2012
Y
Jun. 30, 2011
Y
Jun. 30, 2012
Y
Jun. 30, 2011
Y
Stock Option [Member]
        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expected term, years 7.69 7.27 4.79 5.13 [1]
Expected stock price volatility 29.66% 29.08% 32.20% 30.75% [1]
Risk-free interest rate 1.09% 2.24% 0.89% 1.85% [1]
Expected dividend yield 1.79% 1.34% 1.80% 1.31% [1]
Weighted average grant date fair value (in dollars per share) $ 12.85 $ 19.44 $ 11.57 $ 16.12 [1]
Stock options granted (in shares)     354,934 337,237
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 six months ended June 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.