Mortgage Debt - Mortgage Debt, Additional Information (Details) - Mortgage Debt [Member] - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Weighted-average interest rate of investment debt	3.33%	3.41%
Percent of property level debt with fixed rate	78.00%	76.00%
Percent of property level debt with floating rate and interest caps	15.00%	14.00%
Percent of property level debt with floating rate, without interest caps	7.00%	10.00%
Weighted average cap strike price	1.67%
Total waivers on debt covenants in loan agreements	$ 194.8
Percent of consolidated mortgage balance	8.00%