Quarterly report pursuant to Section 13 or 15(d)

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

v2.4.0.6
Stock-Based Compensation (Schedule Of Weighted Average Assumptions For Restricted Stock Units) (Details) (Restricted Stock Units [Member], USD $)
3 Months Ended 9 Months Ended
Sep. 30, 2012
Y
Sep. 30, 2011
Y
Sep. 30, 2012
Y
Sep. 30, 2011
Y
Restricted Stock Units [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period, years 4.00 4.00 3.86 3.96
Expected dividend yield 1.63% 1.84% 1.77% 1.33%
Estimated average grant date fair value per restricted stock unit (in dollars per share) $ 50.46 $ 44.82 $ 46.57 $ 58.37