Investments in Apartment/Mixed Use Joint Ventures as of December 31, 2021 (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021	Mar. 31, 2021
Schedule of Equity Method Investments [Line Items]
Investments in real estate, net	$ 492,952	$ 472,317
Cash and cash equivalents	4,924	2,987
Unrealized rents & receivables	6,485	4,342
Deferred costs	936	898
Total Assets	677,040	678,190
Secured notes payable	267,426	222,635
Other liabilities	18,705	28,253
Capital – Third Parties	397,802	396,423
Total Liabilities and Capital	677,040	678,190
Real Estate Total Assets [Member]
Schedule of Equity Method Investments [Line Items]
Total Assets	505,297	480,544
Real Estate Partnership F R P [Member]
Schedule of Equity Method Investments [Line Items]
Capital - FRP	131,892	139,981
Real Estate Partnership Third Parties [Member]
Schedule of Equity Method Investments [Line Items]
Capital – Third Parties	87,274	89,675
Real Estate Partnership Total Liabilities And Capital [Member]
Schedule of Equity Method Investments [Line Items]
Total Liabilities and Capital	505,297	480,544
Riverfront Holdings I I L L C [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	0	0
Total Assets			$ 150,082
Secured notes payable	0	0
Other liabilities	0	0
Capital - FRP			18,513
Capital – Third Parties			44,200
Total Liabilities and Capital			$ 150,082
Riverfront Holdings I I L L C [Member] | Real Estate Total Assets [Member]
Schedule of Equity Method Investments [Line Items]
Total Assets	0	0
Riverfront Holdings I I L L C [Member] | Real Estate Partnership F R P [Member]
Schedule of Equity Method Investments [Line Items]
Capital - FRP	0	0
Riverfront Holdings I I L L C [Member] | Real Estate Partnership Third Parties [Member]
Schedule of Equity Method Investments [Line Items]
Capital – Third Parties	0	0
Riverfront Holdings I I L L C [Member] | Real Estate Partnership Total Liabilities And Capital [Member]
Schedule of Equity Method Investments [Line Items]
Total Liabilities and Capital	0	0
Bryant Street Partnerships [Member]
Schedule of Equity Method Investments [Line Items]
Investments in real estate, net	195,633	199,730
Cash and cash equivalents	2,831	1,123
Unrealized rents & receivables	4,859	2,925
Deferred costs	157	304
Secured notes payable	128,697	119,201
Other liabilities	3,077	9,066
Bryant Street Partnerships [Member] | Real Estate Total Assets [Member]
Schedule of Equity Method Investments [Line Items]
Total Assets	203,480	204,082
Bryant Street Partnerships [Member] | Real Estate Partnership F R P [Member]
Schedule of Equity Method Investments [Line Items]
Capital - FRP	54,814	57,555
Bryant Street Partnerships [Member] | Real Estate Partnership Third Parties [Member]
Schedule of Equity Method Investments [Line Items]
Capital – Third Parties	16,892	18,260
Bryant Street Partnerships [Member] | Real Estate Partnership Total Liabilities And Capital [Member]
Schedule of Equity Method Investments [Line Items]
Total Liabilities and Capital	203,480	204,082
D S T Hickory Creek [Member]
Schedule of Equity Method Investments [Line Items]
Investments in real estate, net	43,124	43,840
Cash and cash equivalents	579	827
Unrealized rents & receivables	1,181	1,044
Deferred costs	302	337
Secured notes payable	29,360	29,337
Other liabilities	144	115
D S T Hickory Creek [Member] | Real Estate Total Assets [Member]
Schedule of Equity Method Investments [Line Items]
Total Assets	45,186	46,048
D S T Hickory Creek [Member] | Real Estate Partnership F R P [Member]
Schedule of Equity Method Investments [Line Items]
Capital - FRP	4,179	4,423
D S T Hickory Creek [Member] | Real Estate Partnership Third Parties [Member]
Schedule of Equity Method Investments [Line Items]
Capital – Third Parties	11,503	12,173
D S T Hickory Creek [Member] | Real Estate Partnership Total Liabilities And Capital [Member]
Schedule of Equity Method Investments [Line Items]
Total Liabilities and Capital	45,186	46,048
Half St Owner L L C [Member]
Schedule of Equity Method Investments [Line Items]
Investments in real estate, net	119,311	93,504
Cash and cash equivalents	646	428
Unrealized rents & receivables	0	0
Deferred costs	0	0
Secured notes payable	47,128	18,404
Other liabilities	11,876	14,470
Half St Owner L L C [Member] | Real Estate Total Assets [Member]
Schedule of Equity Method Investments [Line Items]
Total Assets	119,957	93,932
Half St Owner L L C [Member] | Real Estate Partnership F R P [Member]
Schedule of Equity Method Investments [Line Items]
Capital - FRP	37,414	37,478
Half St Owner L L C [Member] | Real Estate Partnership Third Parties [Member]
Schedule of Equity Method Investments [Line Items]
Capital – Third Parties	23,539	23,580
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	119,957	93,932
Greenville Woodfield Partnerships [Member]
Schedule of Equity Method Investments [Line Items]
Investments in real estate, net	92,149	87,421
Cash and cash equivalents	466	279
Unrealized rents & receivables	14	5
Deferred costs	318	26
Secured notes payable	51,148	44,309
Other liabilities	3,402	4,462
Greenville Woodfield Partnerships [Member] | Real Estate Total Assets [Member]
Schedule of Equity Method Investments [Line Items]
Total Assets	92,947	87,731
Greenville Woodfield Partnerships [Member] | Real Estate Partnership F R P [Member]
Schedule of Equity Method Investments [Line Items]
Capital - FRP	15,359	15,584
Greenville Woodfield Partnerships [Member] | Real Estate Partnership Third Parties [Member]
Schedule of Equity Method Investments [Line Items]
Capital – Third Parties	23,038	23,376
Greenville Woodfield Partnerships [Member] | Real Estate Partnership Total Liabilities And Capital [Member]
Schedule of Equity Method Investments [Line Items]
Total Liabilities and Capital	92,947	87,731
Apartment Mixed Use [Member]
Schedule of Equity Method Investments [Line Items]
Investments in real estate, net	450,217	424,495
Cash and cash equivalents	4,522	2,657
Unrealized rents & receivables	6,054	3,974
Deferred costs	777	667
Secured notes payable	256,333	211,251
Other liabilities	18,499	28,113
Apartment Mixed Use [Member] | Real Estate Total Assets [Member]
Schedule of Equity Method Investments [Line Items]
Total Assets	461,570	431,793
Apartment Mixed Use [Member] | Real Estate Partnership F R P [Member]
Schedule of Equity Method Investments [Line Items]
Capital - FRP	111,766	115,040
Apartment Mixed Use [Member] | Real Estate Partnership Third Parties [Member]
Schedule of Equity Method Investments [Line Items]
Capital – Third Parties	74,972	77,389
Apartment Mixed Use [Member] | Real Estate Partnership Total Liabilities And Capital [Member]
Schedule of Equity Method Investments [Line Items]
Total Liabilities and Capital	$ 461,570	$ 431,793