XML 60 R45.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Stock-Based Compensation (Schedule of Assumptions Used to Estimate Weighted-Average Fair Value of Options Granted) (Details)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]      
Dividend yield 3.30% 3.90% 3.20%
Volatility 17.00% 20.80% 15.60%
Risk-free interest rate 2.30% 2.80% 1.80%
Expected life - years 4 years 7 months 6 days 4 years 7 months 6 days 4 years 7 months 6 days