Income Taxes - Tax Status of Dividends (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Tax Status of Dividends [Line Items]
Dividend per share	$ 2.34	$ 2.22	$ 2.10
Ordinary income	97.00%	98.00%	86.00%
Capital gain	3.00%	0.00%	10.00%
Return of capital	0.00%	0.00%	4.00%
Allocation of Dividends, Qualified Dividend Income	0.00%	2.00%	0.00%
Allocation of Dividends, Section 199A Dividend	97.00%	98.00%	0.00%
Parent Company [Member]
Schedule of Tax Status of Dividends [Line Items]
Dividend per share	$ 2.34	$ 2.22	$ 2.10