MARKETABLE SECURITIES (Details Narrative) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Marketable Securities [Line Items]
Available marketable securities	$ 108,200,000
Percentage of undepreciated assets	7.70%
Sale of marketable securities	$ 4,509,000	$ 0
Loss on Sales of Marketable Securities, net	730,000	$ (0)
Increase in fair value of marketable securities	10,200,000
Marketable Securities [Member]
Marketable Securities [Line Items]
Sale of marketable securities	5,200,000
Loss on Sales of Marketable Securities, net	$ 730,000
Real Estate Investment Trusts [Member]
Marketable Securities [Line Items]
Number Of Individual Securities	15.00%
Total net unrealized holding losses	$ 29,100,000
Monmouth Real Estate Investment Corporation [Member]
Marketable Securities [Line Items]
Number of common stock owned, shares	2,700,000
Number of common stock owned, value	$ 25,000,000.0
Number of common stock owned, fair value	$ 47,000,000.0