Mortgages Payable - Summary of Mortgages Payable (Details) - Mortgages payable $ in Thousands	Mar. 31, 2021 USD ($) mortgage property	Dec. 31, 2020 USD ($) mortgage property
Debt
Number of Properties | property	64	68
Weighted Average Stated Interest Rate (as a percent)	4.80%	4.90%
Weighted Average Effective Interest Rate (as a percent)	4.60%	4.60%
Weighted Average Remaining Years Until Maturity	2 years 9 months 18 days	2 years 10 months 24 days
Remaining Principal Balance	$ 281,521	$ 299,631
Unamortized Premium and Deferred Finance Costs Balance, net	516	729
Net payable amount	$ 282,037	$ 300,360
Number of mortgages | mortgage	15	18
Minimum
Debt
Weighted Average Effective Interest Rate (as a percent)	4.00%	4.00%
Stated interest rate (as a percent)	3.80%	3.80%
Maximum
Debt
Weighted Average Effective Interest Rate (as a percent)	5.50%	5.50%
Stated interest rate (as a percent)	6.90%	6.90%