Quarterly report pursuant to Section 13 or 15(d)

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

v3.8.0.1
Stock-Based Compensation (Schedule Of Weighted Average Assumptions) (Details) - Stock Option [Member] - $ / shares
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected term, years 4 years 3 months 22 days 4 years 4 months 2 days
Expected stock price volatility 28.48% 28.95%
Risk-free interest rate 2.43% 1.70%
Expected annual dividend yield 1.17% 1.30%
Weighted average grant date fair value (in dollars per share) $ 18.10 $ 12.73