Share-Based Payments (Weighted Average Grant Date Assumptions Used in Binomial Optional Valuation Model) (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Payment Arrangement [Abstract]
Expected volatility	34.63%	35.39%	35.29%
Expected dividend yield	4.26%	2.88%	2.84%
Expected term	5 years 6 months 14 days	5 years 5 months 26 days	5 years 7 months 6 days
Risk-free interest rate	2.50%	2.64%	2.06%