Income Taxes - Tax Status of Dividends (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule of Tax Status of Dividends [Line Items]
Dividend per share	$ 2.38	$ 2.34	$ 2.22
Ordinary income	100.00%	97.00%	98.00%
Capital gain	0.00%	3.00%	0.00%
Allocation of Dividends, Qualified Dividend Income	0.00%	0.00%	2.00%
Allocation of Dividends, Section 199A Dividend	100.00%	97.00%	98.00%
Parent Company [Member]
Schedule of Tax Status of Dividends [Line Items]
Dividend per share	$ 2.19	$ 2.34	$ 2.22