Aggregate Principal Amounts due on Mortgage and Construction Notes Payable by Unconsolidated LLC's/LPs Accounted Under Equity Method (Detail) - Equity Method Investments - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2021	Dec. 31, 2020
Schedule Of Equity Method Investments [Line Items]
Mortgage Loan Balance	[1]	$ 22,133	$ 39,735
FTX MOB Phase II
Schedule Of Equity Method Investments [Line Items]
Mortgage Loan Balance	[1],[2]		4,777
Debt Instrument Maturity Date	[2]	2021-02
Grayson Properties
Schedule Of Equity Method Investments [Line Items]
Mortgage Loan Balance	[1],[3]		13,372
Debt Instrument Maturity Date	[3]	2021-09
Brunswick Associates
Schedule Of Equity Method Investments [Line Items]
Mortgage Loan Balance	[1]	$ 9,058	9,250
Debt Instrument Maturity Date		2030-12
Grayson Properties Two L P
Schedule Of Equity Method Investments [Line Items]
Mortgage Loan Balance	[1],[4]	$ 13,075	$ 12,336
Debt Instrument Maturity Date	[4]	2025-06

[1] All mortgage loans require monthly principal payments through maturity and include a balloon principal payment upon maturity

[2] Upon maturity in February 2021 this LP paid off this mortgage loan utilizing pro rata equity contributions from the limited partners as well as a $3.5 million member loan from us to the LP which was funded utilizing borrowings from our revolving credit agreement.

[3] Upon maturity in September, 2021 this LP paid off this mortgage utilizing an equity contribution from us, which was funded utilizing borrowings from our revolving credit agreement.

[4] This construction loan has a maximum commitment of $13.1 million and requires interest on the outstanding principal balance to be paid on a monthly basis through December 1, 2022.  Monthly principal and interest payments are scheduled to commence on January 1, 2023.