Mortgages Payable - Summary of Mortgages Payable (Details) - Mortgages payable $ in Thousands	Jun. 30, 2021 USD ($) property mortgage	Dec. 31, 2020 USD ($) property mortgage
Debt
Number of Properties | property	62	68
Weighted Average Stated Interest Rate (as a percent)	4.50%	4.90%
Weighted Average Effective Interest Rate (as a percent)	4.30%	4.60%
Weighted Average Remaining Years Until Maturity	2 years 10 months 24 days	2 years 10 months 24 days
Remaining Principal Balance	$ 299,901	$ 299,631
Unamortized Premium and Deferred Finance Costs Balance, net	673	729
Net payable amount	$ 300,574	$ 300,360
Number of mortgages | mortgage	14	18
Minimum
Debt
Weighted Average Effective Interest Rate (as a percent)	2.80%	4.00%
Stated interest rate (as a percent)	3.00%	3.80%
Maximum
Debt
Weighted Average Effective Interest Rate (as a percent)	5.10%	5.50%
Stated interest rate (as a percent)	6.90%	6.90%