XML 49 R39.htm IDEA: XBRL DOCUMENT v3.21.1
Stock-based Compensation (Schedule of Stock Options Weight Average Assumptions) (Details) - Stock Options [Member] - $ / shares
3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Assumptions For Stock Awards [Abstract]    
Risk-free interest rate at date of grant 0.40% 1.50%
Dividend yield 1.90% 2.10%
Expected life (years) 4 years 7 months 6 days 4 years 10 months 24 days
Volatility 28.30% 23.40%
Weighted-average grant-date fair value of options granted $ 39.97 $ 32.20