Unsecured Lines of Credit - Additional Information (Details) - USD ($)	Aug. 31, 2021	Jun. 30, 2021	Dec. 31, 2020
Bankers Trust Operating [Member]
Line Of Credit Facility [Line Items]
Outstanding principal		$ 0
BankUnited, N.A. and Bankers Trust Company [Member]
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity		40,000,000
Unsecured Lines of Credit [Member]
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity			$ 60,000,000
Unsecured Lines of Credit [Member] | Bankers Trust Operating [Member]
Line Of Credit Facility [Line Items]
Termination of operating LOC		$ 10,000,000
Unsecured Lines of Credit [Member] | Bankers Trust Non-operating [Member]
Line Of Credit Facility [Line Items]
Outstanding principal	$ 0
Termination of non-operating LOC	$ 50,000,000