Share Based Compensation - Weighted Average and Assumptions (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Payment Arrangement [Abstract]
Weighted-average estimated fair value	$ 22.23	$ 21.87	$ 19.40
Quarterly dividend rate	$ 0.46	$ 0.44	$ 0.42
Expected term of stock options, in years	4 years 2 months 12 days	4 years 6 months	4 years 8 months 12 days
Risk-free interest rate	2.50%	2.40%	1.90%
Dividend yield	2.60%	2.50%	2.80%
Expected stock price volatility	28.90%	27.90%	27.70%
Present value of dividends	$ 7.29	$ 7.51	$ 7.50