Investments in Joint Ventures (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2013	Oct. 04, 2006
Net Loss of the Partnership		$ (1,454)		$ (2,057)
Company's share of Net Loss of the Partnership	$ (806)	$ (1,119)	$ (186)	(1,577)	$ (272)
Total revenues	9,360		9,243	18,682	18,858
Operating expenses	5,374		7,277	11,292	13,383
Property taxes	1,129		1,128	2,191	2,270
Total cost of operations	1,002		974	2,003	2,505
Total operating profit	3,986		1,966	7,390	5,475
Interest expense	$ (371)		(392)	$ (619)	(807)
Riverfront Holdings I, LLC
Ownership percent	77.14%	77.14%		77.14%		77.14%
Total Investment	$ 8,583	$ 10,151		$ 8,583
Total Assets of the Partnership	91,641	90,420		91,641
Net Loss of the Partnership		(1,446)		(2,019)
Company's share of Net Loss of the Partnership		(1,115)		(1,558)
Cash	2,295	1,023		2,295
Cash held in escrow	171	88		171
Accounts receivable	40			40
Prepaid expenses	142			142
Investments in real estate, net	88,993	89,309		88,993
Amortizable debt costs	(852)			(852)
Other liabilities	905	6,348		905
Long-term debt	78,587	69,042		78,587
Capital - FRP	8,583	10,151		8,583
Capital - Third parties	4,418	4,879		4,418
Total liabilities and capital	91,641	$ 90,420		91,641
Rental revenue	1,742		0	3,053	0
Revenue - Reimbursements	18		0	33	0
Total revenues	1,760		0	3,086	0
Depreciation and amortization	1,095		75	1,958	97
Operating expenses	621		148	1,096	216
Property taxes	240		0	459	0
Total cost of operations	1,956		223	3,513	313
Total operating profit	(196)		(223)	(427)	(313)
Interest expense	(836)		0	(1,592)	0
Net loss of the Partnership	$ (1,032)		$ (223)	$ (2,019)	$ (313)
Brooksville Quarry, LLC
Ownership percent	50.00%	50.00%		50.00%			50.00%
Total Investment	$ 7,500	$ 7,522		$ 7,500
Total Assets of the Partnership	14,343	14,341		14,343
Net Loss of the Partnership		(8)		(38)
Company's share of Net Loss of the Partnership		(4)		(19)
Cash	26	18		26
Cash held in escrow	0	0		0
Accounts receivable	6			6
Prepaid expenses	2			2
Investments in real estate, net	14,309	14,323		14,309
Amortizable debt costs	0			0
Other liabilities	45	1		45
Long-term debt	0	0		0
Capital - FRP	7,500	7,522		7,500
Capital - Third parties	6,798	6,818		6,798
Total liabilities and capital	$ 14,343	$ 14,341		$ 14,343
BC FRP Realty, LLC
Ownership percent	50.00%	50.00%		50.00%
Total Investment	$ 5,474	$ 5,228		$ 5,474
Total Assets of the Partnership	11,113	10,784		11,113
Net Loss of the Partnership		0		0
Company's share of Net Loss of the Partnership		0		0
Cash	44	21		44
Cash held in escrow	0	0		0
Accounts receivable	0			0
Prepaid expenses	0			0
Investments in real estate, net	11,069	10,763		11,069
Amortizable debt costs	0			0
Other liabilities	0	47		0
Long-term debt	0	0		0
Capital - FRP	5,474	5,228		5,474
Capital - Third parties	5,639	5,509		5,639
Total liabilities and capital	11,113	10,784		11,113
Joint Ventures
Total Investment	21,557	22,901		21,557
Total Assets of the Partnership	117,097	115,545		117,097
Cash	2,365	1,062		2,365
Cash held in escrow	171	88		171
Accounts receivable	46			46
Prepaid expenses	144			144
Investments in real estate, net	114,371	114,395		114,371
Amortizable debt costs	(852)			(852)
Other liabilities	950	6,396		950
Long-term debt	78,587	69,042		78,587
Capital - FRP	21,557	22,901		21,557
Capital - Third parties	16,855	17,206		16,855
Total liabilities and capital	$ 117,097	$ 115,545		$ 117,097