Investments in Joint Ventures as of September 30, 2023 (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Schedule of Equity Method Investments [Line Items]
Investments in real estate, net	$ 498,119	$ 493,324
Cash and cash equivalents	8,814	7,937
Unrealized rents & receivables	6,990	5,577
Deferred costs	5,838	3,802
Total Assets	701,157	701,084
Secured notes payable	273,938	276,801
Other liabilities	6,635	11,023
Capital - Third Parties	410,790	407,145
Total Liabilities and Capital	701,157	701,084
Real Estate Total Assets [Member]
Schedule of Equity Method Investments [Line Items]
Total Assets	519,761	510,640
Real Estate Partnership F R P [Member]
Schedule of Equity Method Investments [Line Items]
Capital – FRP	148,740	135,333
Real Estate Partnership Third Parties [Member]
Schedule of Equity Method Investments [Line Items]
Capital - Third Parties	90,448	87,483
Real Estate Partnership Total Liabilities And Capital [Member]
Schedule of Equity Method Investments [Line Items]
Total Liabilities and Capital	519,761	510,640
Brooksville Quarry L L C [Member]
Schedule of Equity Method Investments [Line Items]
Investments in real estate, net	14,343	14,307
Cash and cash equivalents	27	66
Unrealized rents & receivables	0	0
Deferred costs	2	1
Secured notes payable	0	0
Other liabilities	64	0
Brooksville Quarry L L C [Member] | Real Estate Total Assets [Member]
Schedule of Equity Method Investments [Line Items]
Total Assets	14,372	14,374
Brooksville Quarry L L C [Member] | Real Estate Partnership F R P [Member]
Schedule of Equity Method Investments [Line Items]
Capital – FRP	7,487	7,522
Brooksville Quarry L L C [Member] | Real Estate Partnership Third Parties [Member]
Schedule of Equity Method Investments [Line Items]
Capital - Third Parties	6,821	6,852
Brooksville Quarry L L C [Member] | Real Estate Partnership Total Liabilities And Capital [Member]
Schedule of Equity Method Investments [Line Items]
Total Liabilities and Capital	14,372	14,374
B C F R P Realty L L C [Member]
Schedule of Equity Method Investments [Line Items]
Investments in real estate, net	21,260	21,059
Cash and cash equivalents	74	99
Unrealized rents & receivables	457	422
Deferred costs	373	245
Secured notes payable	11,856	10,899
Other liabilities	266	338
B C F R P Realty L L C [Member] | Real Estate Total Assets [Member]
Schedule of Equity Method Investments [Line Items]
Total Assets	22,164	21,825
B C F R P Realty L L C [Member] | Real Estate Partnership F R P [Member]
Schedule of Equity Method Investments [Line Items]
Capital – FRP	5,021	5,294
B C F R P Realty L L C [Member] | Real Estate Partnership Third Parties [Member]
Schedule of Equity Method Investments [Line Items]
Capital - Third Parties	5,021	5,294
B C F R P Realty L L C [Member] | Real Estate Partnership Total Liabilities And Capital [Member]
Schedule of Equity Method Investments [Line Items]
Total Liabilities and Capital	22,164	21,825
Lending Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Investments in real estate, net	14,428	5,547
Cash and cash equivalents	0	0
Unrealized rents & receivables	0	0
Deferred costs	0	30
Secured notes payable	(10,656)	(10,899)
Other liabilities	0	0
Lending Ventures [Member] | Real Estate Total Assets [Member]
Schedule of Equity Method Investments [Line Items]
Total Assets	14,428	5,577
Lending Ventures [Member] | Real Estate Partnership F R P [Member]
Schedule of Equity Method Investments [Line Items]
Capital – FRP	25,084	16,476
Lending Ventures [Member] | Real Estate Partnership Third Parties [Member]
Schedule of Equity Method Investments [Line Items]
Capital - Third Parties	0	0
Lending Ventures [Member] | Real Estate Partnership Total Liabilities And Capital [Member]
Schedule of Equity Method Investments [Line Items]
Total Liabilities and Capital	14,428	5,577
Apartment Mixed Use [Member]
Schedule of Equity Method Investments [Line Items]
Investments in real estate, net	448,088	452,411
Cash and cash equivalents	8,713	7,772
Unrealized rents & receivables	6,533	5,155
Deferred costs	5,463	3,526
Secured notes payable	272,738	276,801
Other liabilities	6,305	10,685
Apartment Mixed Use [Member] | Real Estate Total Assets [Member]
Schedule of Equity Method Investments [Line Items]
Total Assets	468,797	468,864
Apartment Mixed Use [Member] | Real Estate Partnership F R P [Member]
Schedule of Equity Method Investments [Line Items]
Capital – FRP	111,148	106,041
Apartment Mixed Use [Member] | Real Estate Partnership Third Parties [Member]
Schedule of Equity Method Investments [Line Items]
Capital - Third Parties	78,606	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	$ 468,797	$ 468,864