XML 91 R85.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Assumptions Used in Valuation of Issued Stock Options (Details)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]      
Risk-free interest rate 2.00% 2.90% 2.00%
Expected life in years 7 years 3 months 18 days 7 years 3 months 18 days 6 years 10 months 24 days
Expected volatility 17.20% 17.10% 16.70%
Dividend yield 1.20% 1.70% 1.40%