Investments in Apartment/Mixed-Use Joint Ventures as of December 31, 2022 (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Schedule of Equity Method Investments [Line Items]
Investments in real estate, net	$ 495,278	$ 493,324
Cash and cash equivalents	10,337	7,937
Unrealized rents & receivables	5,756	5,577
Deferred costs	4,684	3,802
Total Assets	699,599	701,084
Secured notes payable	283,771	276,801
Other liabilities	5,907	11,023
Capital – Third Parties	409,211	407,145
Total Liabilities and Capital	699,599	701,084
Real Estate Total Assets [Member]
Schedule of Equity Method Investments [Line Items]
Total Assets	516,055	510,640
Real Estate Partnership F R P [Member]
Schedule of Equity Method Investments [Line Items]
Capital - FRP	139,459	135,333
Real Estate Partnership Third Parties [Member]
Schedule of Equity Method Investments [Line Items]
Capital – Third Parties	86,918	87,483
Real Estate Partnership Total Liabilities And Capital [Member]
Schedule of Equity Method Investments [Line Items]
Total Liabilities and Capital	516,055	510,640
Buzzard Point Sponsor Partnership [Member]
Schedule of Equity Method Investments [Line Items]
Investments in real estate, net	0	0
Cash and cash equivalents	0	0
Unrealized rents & receivables	0	0
Deferred costs	3,778	2,906
Secured notes payable	0	0
Other liabilities	0	0
Buzzard Point Sponsor Partnership [Member] | Real Estate Total Assets [Member]
Schedule of Equity Method Investments [Line Items]
Total Assets	3,778	2,906
Buzzard Point Sponsor Partnership [Member] | Real Estate Partnership F R P [Member]
Schedule of Equity Method Investments [Line Items]
Capital - FRP	1,889	1,453
Buzzard Point Sponsor Partnership [Member] | Real Estate Partnership Third Parties [Member]
Schedule of Equity Method Investments [Line Items]
Capital – Third Parties	1,889	1,453
Buzzard Point Sponsor Partnership [Member] | Real Estate Partnership Total Liabilities And Capital [Member]
Schedule of Equity Method Investments [Line Items]
Total Liabilities and Capital	3,778	2,906
Bryant Street Partnerships [Member]
Schedule of Equity Method Investments [Line Items]
Investments in real estate, net	191,753	192,904
Cash and cash equivalents	1,496	1,349
Unrealized rents & receivables	5,189	5,128
Deferred costs	303	393
Secured notes payable	129,451	129,263
Other liabilities	2,411	2,338
Bryant Street Partnerships [Member] | Real Estate Total Assets [Member]
Schedule of Equity Method Investments [Line Items]
Total Assets	198,741	199,774
Bryant Street Partnerships [Member] | Real Estate Partnership F R P [Member]
Schedule of Equity Method Investments [Line Items]
Capital - FRP	52,953	53,553
Bryant Street Partnerships [Member] | Real Estate Partnership Third Parties [Member]
Schedule of Equity Method Investments [Line Items]
Capital – Third Parties	13,926	14,620
Bryant Street Partnerships [Member] | Real Estate Partnership Total Liabilities And Capital [Member]
Schedule of Equity Method Investments [Line Items]
Total Liabilities and Capital	198,741	199,774
Estero Partnership [Member]
Schedule of Equity Method Investments [Line Items]
Investments in real estate, net	33,076	33,008
Cash and cash equivalents	5,424	5,497
Unrealized rents & receivables	0	0
Deferred costs	0	0
Secured notes payable	16,000	16,000
Other liabilities	0	5
Estero Partnership [Member] | Real Estate Total Assets [Member]
Schedule of Equity Method Investments [Line Items]
Total Assets	38,500	38,505
Estero Partnership [Member] | Real Estate Partnership F R P [Member]
Schedule of Equity Method Investments [Line Items]
Capital - FRP	3,600	3,600
Estero Partnership [Member] | Real Estate Partnership Third Parties [Member]
Schedule of Equity Method Investments [Line Items]
Capital – Third Parties	18,900	18,900
Estero Partnership [Member] | Real Estate Partnership Total Liabilities And Capital [Member]
Schedule of Equity Method Investments [Line Items]
Total Liabilities and Capital	38,500	38,505
Half St Owner L L C [Member]
Schedule of Equity Method Investments [Line Items]
Investments in real estate, net	131,055	130,616
Cash and cash equivalents	2,762	359
Unrealized rents & receivables	106	14
Deferred costs	137	139
Secured notes payable	71,631	66,584
Other liabilities	1,195	5,328
Half St Owner L L C [Member] | Real Estate Total Assets [Member]
Schedule of Equity Method Investments [Line Items]
Total Assets	134,060	131,128
Half St Owner L L C [Member] | Real Estate Partnership F R P [Member]
Schedule of Equity Method Investments [Line Items]
Capital - FRP	38,051	36,348
Half St Owner L L C [Member] | Real Estate Partnership Third Parties [Member]
Schedule of Equity Method Investments [Line Items]
Capital – Third Parties	23,183	22,868
Half St Owner L L C [Member] | Real Estate Partnership Total Liabilities And Capital [Member]
Schedule of Equity Method Investments [Line Items]
Total Liabilities and Capital	134,060	131,128
Greenville Partnerships [Member]
Schedule of Equity Method Investments [Line Items]
Investments in real estate, net	95,108	95,883
Cash and cash equivalents	478	567
Unrealized rents & receivables	49	13
Deferred costs	158	88
Secured notes payable	66,689	64,954
Other liabilities	1,733	3,014
Greenville Partnerships [Member] | Real Estate Total Assets [Member]
Schedule of Equity Method Investments [Line Items]
Total Assets	95,793	96,551
Greenville Partnerships [Member] | Real Estate Partnership F R P [Member]
Schedule of Equity Method Investments [Line Items]
Capital - FRP	10,399	11,087
Greenville Partnerships [Member] | Real Estate Partnership Third Parties [Member]
Schedule of Equity Method Investments [Line Items]
Capital – Third Parties	16,972	17,496
Greenville Partnerships [Member] | Real Estate Partnership Total Liabilities And Capital [Member]
Schedule of Equity Method Investments [Line Items]
Total Liabilities and Capital	95,793	96,551
Apartment Mixed Use [Member]
Schedule of Equity Method Investments [Line Items]
Investments in real estate, net	450,992	452,411
Cash and cash equivalents	10,160	7,772
Unrealized rents & receivables	5,344	5,155
Deferred costs	4,376	3,526
Secured notes payable	283,771	276,801
Other liabilities	5,339	10,685
Apartment Mixed Use [Member] | Real Estate Total Assets [Member]
Schedule of Equity Method Investments [Line Items]
Total Assets	470,872	468,864
Apartment Mixed Use [Member] | Real Estate Partnership F R P [Member]
Schedule of Equity Method Investments [Line Items]
Capital - FRP	106,892	106,041
Apartment Mixed Use [Member] | Real Estate Partnership Third Parties [Member]
Schedule of Equity Method Investments [Line Items]
Capital – Third Parties	74,870	75,337
Apartment Mixed Use [Member] | Real Estate Partnership Total Liabilities And Capital [Member]
Schedule of Equity Method Investments [Line Items]
Total Liabilities and Capital	$ 470,872	$ 468,864