Maren consolidation at stabilization (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Condensed Cash Flow Statements, Captions [Line Items]
Land	$ 121,057		$ 91,744
Project under construction	11,378		4,879
Accounts receivable	1,076		923
Total Assets	681,252		536,360
Long-term Debt	178,334		89,964
Other liabilities	1,886		1,886
Equity – FRP	396,561		367,654
Total Liabilities and Capital	$ 681,252		$ 536,360
Riverfront Holdings I I L L C [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Land		$ 29,330
Building and improvements, net		110,800
Project under construction		258
Value of leases in place		4,750
Cash		3,704
Cash held in escrow		336
Accounts receivable		707
Prepaid expenses		197
Total Assets		150,082
Long-term Debt		88,000
Amortizable debt costs		(1,072)
Other liabilities		441
Equity – FRP		44,200
Equity - MRP		18,513
Total Liabilities and Capital		150,082
Riverfront Holdings I I L L C [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Land		6,472
Building and improvements, net		87,269
Project under construction		258
Value of leases in place		0
Cash		3,704
Cash held in escrow		336
Accounts receivable		707
Prepaid expenses		197
Total Assets		98,943
Long-term Debt		88,000
Amortizable debt costs		(1,072)
Other liabilities		441
Equity – FRP		7,026
Equity - MRP		4,548
Total Liabilities and Capital		98,943
Remeasurement Gain [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Land		22,858
Building and improvements, net		23,531
Project under construction		0
Value of leases in place		4,750
Cash		0
Cash held in escrow		0
Accounts receivable		0
Prepaid expenses		0
Total Assets		51,139
Long-term Debt		0
Amortizable debt costs		0
Other liabilities		0
Equity – FRP		37,174
Equity - MRP		13,965
Total Liabilities and Capital		$ 51,139