Mortgages and Other Notes Payable - Schedule of Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Mortgages and other notes payable	$ 154,959	$ 176,750
Mortgages and other notes payable | 770 South Post Oak
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Mortgages and other notes payable	$ 11,484	11,635
Effective Interest Rate	4.40%
Mortgages and other notes payable | Athens
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Mortgages and other notes payable	$ 1,155	1,155
Effective Interest Rate	4.00%
Mortgages and other notes payable | Chelsea
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Mortgages and other notes payable	$ 7,916	8,037
Effective Interest Rate	3.40%
Mortgages and other notes payable | EQK Portage
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Mortgages and other notes payable	$ 3,350	3,350
Effective Interest Rate	10.00%
Mortgages and other notes payable | Forest Grove
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Mortgages and other notes payable	$ 7,163	7,263
Effective Interest Rate	3.75%
Mortgages and other notes payable | Landing Bayou
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Mortgages and other notes payable	$ 14,224	14,407
Effective Interest Rate	3.50%
Mortgages and other notes payable | Legacy at Pleasant Grove
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Mortgages and other notes payable	$ 13,119	13,352
Effective Interest Rate	3.60%
Mortgages and other notes payable | Parc at Denham Springs Phase II
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Mortgages and other notes payable	$ 15,833	15,962
Effective Interest Rate	4.10%
Mortgages and other notes payable | RCM HC Enterprises
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Mortgages and other notes payable	$ 5,086	1,986
Effective Interest Rate	5.00%
Mortgages and other notes payable | Standford Center
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Mortgages and other notes payable	$ 38,567	38,979
Effective Interest Rate	6.00%
Mortgages and other notes payable | Sugar Mill Phase III
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Mortgages and other notes payable	$ 0	9,216
Effective Interest Rate	4.50%
Mortgages and other notes payable | Toulon
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Mortgages and other notes payable	$ 0	13,697
Effective Interest Rate	3.20%
Mortgages and other notes payable | Villas at Bon Secour
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Mortgages and other notes payable	$ 19,504	19,492
Effective Interest Rate	3.08%
Mortgages and other notes payable | Vista Ridge
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Mortgages and other notes payable	$ 9,714	9,830
Effective Interest Rate	4.00%
Mortgages and other notes payable | Windmill Farms
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Mortgages and other notes payable	$ 7,844	$ 8,389
Effective Interest Rate	5.00%