Equity - Tax Treatment of Dividends Paid (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Dividends Payable [Line Items]
Tax treatment of capital gain dividends, percent	100.00%	100.00%	100.00%
Capital gains
Dividends Payable [Line Items]
Tax treatment of capital gain dividends, percent	10.62%	9.49%	9.06%
Ordinary income
Dividends Payable [Line Items]
Tax treatment of capital gain dividends, percent	68.83%	63.40%	71.59%
Return of capital
Dividends Payable [Line Items]
Tax treatment of capital gain dividends, percent	20.55%	27.11%	19.35%