Equity (Weighted Average Assumptions Used to Determine Fair Value of Stock Options) (Details) - Stock Options	12 Months Ended
	Dec. 31, 2018 $ / shares	Dec. 31, 2017 $ / shares	Dec. 31, 2016 $ / shares
Equity - Stock-based Compensation Plans [Line Items]
Dividend yield	3.52%	3.05%	3.90%
Risk-free rate of return, Minimum	2.02%	0.94%	0.62%
Risk-free rate of return, Maximum	3.40%	3.22%	2.85%
Expected volatility	34.18%	34.19%	33.58%
Exercise multiple	1.43	1.43	1.43
Post-vesting termination rate	3.77%	2.94%	2.58%
Contractual term (years)	10 years	10 years	10 years
Expected life (years)	6 years	6 years	7 years
Weighted average exercise price of stock options granted	$ 45.50	$ 46.85	$ 34.33
Weighted average fair value of stock options granted	$ 11.87	$ 12.36	$ 8.27