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 6 Months Ended
Jun. 30, 2012
Y
Jun. 30, 2011
Y
Jun. 30, 2012
Y
Jun. 30, 2011
Y
Restricted Stock Units [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period, years 2.90 3.33 3.84 3.96
Expected dividend yield 1.78% 1.31% 1.79% 1.30%
Estimated average grant date fair value per restricted stock unit (in dollars per share) $ 46.90 $ 64.06 $ 45.96 $ 59.06