SCHEDULE IV - MORTGAGE LOANS - Schedule of Mortgage Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens	$ 301,975
Face Amount	129,726
Carrying Value	129,726	$ 123,556	$ 112,357	$ 83,541
Convertible loans
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens	205,046
Face Amount	40,114
Carrying Value	$ 40,114
Convertible loans | Autumn Breeze
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	5.00%
Prior Liens	$ 24,756
Face Amount	2,486
Carrying Value	$ 2,486
Convertible loans | Bellwether Ridge
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	5.00%
Prior Liens	$ 18,070
Face Amount	3,967
Carrying Value	$ 3,967
Convertible loans | Forest Pines
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	5.00%
Prior Liens	$ 26,407
Face Amount	6,472
Carrying Value	$ 6,472
Convertible loans | Parc at Ingleside
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	5.00%
Prior Liens	$ 25,201
Face Amount	3,700
Carrying Value	$ 3,700
Convertible loans | Parc at Opelika
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	10.00%
Prior Liens	$ 23,661
Face Amount	2,305
Carrying Value	$ 2,305
Convertible loans | Parc at Windmill Farms
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	5.00%
Prior Liens	$ 35,524
Face Amount	7,830
Carrying Value	$ 7,830
Convertible loans | Plum Tree
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	5.00%
Prior Liens	$ 17,105
Face Amount	1,537
Carrying Value	$ 1,537
Convertible loans | Spyglass of Ennis
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	5.00%
Prior Liens	$ 22,793
Face Amount	5,319
Carrying Value	$ 5,319
Convertible loans | Steeple Crest
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	5.00%
Prior Liens	$ 11,529
Face Amount	6,498
Carrying Value	6,498
Land loans
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens	0
Face Amount	22,348
Carrying Value	$ 22,348
Land loans | ABC Land and Development, Inc.
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	9.50%
Prior Liens	$ 0
Face Amount	4,408
Carrying Value	$ 4,408
Land loans | ABC Paradise, LLC
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	9.50%
Prior Liens	$ 0
Face Amount	1,210
Carrying Value	$ 1,210
Land loans | Lake Wales
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	9.50%
Prior Liens	$ 0
Face Amount	3,000
Carrying Value	$ 3,000
Land loans | Legacy Pleasant Grove
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	12.00%
Prior Liens	$ 0
Face Amount	496
Carrying Value	$ 496
Land loans | McKinney Ranch
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	6.00%
Prior Liens	$ 0
Face Amount	4,554
Carrying Value	$ 4,554
Land loans | One Realco Land Holding, Inc.
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	9.50%
Prior Liens	$ 0
Face Amount	1,728
Carrying Value	$ 1,728
Land loans | Riverview on the Park Land, LLC
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	9.50%
Prior Liens	$ 0
Face Amount	1,045
Carrying Value	$ 1,045
Land loans | Spartan Land
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	12.00%
Prior Liens	$ 0
Face Amount	5,907
Carrying Value	5,907
Subsidized housing
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens	96,929
Face Amount	67,264
Carrying Value	$ 67,264
Subsidized housing | Phillips Foundation for Better Living, Inc.
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	12.00%
Prior Liens	$ 0
Face Amount	813
Carrying Value	$ 813
Subsidized housing | Unified Housing Foundation Inc., Maturing July 31, 2021
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	12.00%
Prior Liens	$ 0
Face Amount	2,881
Carrying Value	$ 2,881
Subsidized housing | Unified Housing Foundation Inc ., Maturing August 30, 2021
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	12.00%
Prior Liens	$ 0
Face Amount	212
Carrying Value	$ 212
Subsidized housing | Unified Housing Foundation Inc., Maturing October 31, 2021
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	12.00%
Prior Liens	$ 0
Face Amount	6,831
Carrying Value	$ 6,831
Subsidized housing | Unified Housing Foundation Inc., Maturing December 31, 2021
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	12.00%
Prior Liens	$ 0
Face Amount	10,401
Carrying Value	$ 10,401
Subsidized housing | Unified Housing Foundation Inc., Maturing March 31, 2022
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	12.00%
Prior Liens	$ 0
Face Amount	10,096
Carrying Value	$ 10,096
Subsidized housing | Unified Housing Foundation Inc., Maturing March 31, 2023
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	12.00%
Prior Liens	$ 0
Face Amount	6,990
Carrying Value	$ 6,990
Subsidized housing | Unified Housing Foundation Inc., Maturing May 31, 2023
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	12.00%
Prior Liens	$ 0
Face Amount	3,615
Carrying Value	$ 3,615
Subsidized housing | Unified Housing Foundation Inc., Maturing December 31, 2032
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	12.00%
Prior Liens	$ 96,929
Face Amount	17,172
Carrying Value	$ 17,172
Subsidized housing | Unified Housing Foundation Inc., Maturing March 31, 2024
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	12.00%
Prior Liens	$ 0
Face Amount	6,521
Carrying Value	$ 6,521
Subsidized housing | Unified Housing Foundation Inc., Maturing April 30, 2024
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	12.00%
Prior Liens	$ 0
Face Amount	1,549
Carrying Value	$ 1,549
Subsidized housing | Unified Housing Foundation Inc., Maturing June 30, 2024
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	12.00%
Prior Liens	$ 0
Face Amount	183
Carrying Value	$ 183