REVENUE RECOGNITION - Major Good or Service (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues
Lease Revenue	$ 9,389,000	$ 7,275,000
Lease Incentive Amortization	(76,000)
Interest from Commercial Loan Investments	301,000	537,000
Total Revenues	24,851,599	38,713,284
Lease Revenue - Base Rent
Revenues
Lease Revenue	7,433,000	5,565,000
Lease Revenue - CAM
Revenues
Lease Revenue	614,000	499,000
Lease Revenue - Reimbursements
Revenues
Lease Revenue	565,000	420,000
Lease Revenue - Billboards
Revenues
Lease Revenue	64,000	61,000
Above / Below Market Lease Accretion
Revenues
Lease Revenue	580,000	531,000
Contributed Leased Assets Accretion
Revenues
Lease Revenue	10,000
Land
Revenues
Revenue from contract with customer, including assessed tax	13,117,000
Land | Calculated under Revenue Guidance in Effect before Topic 606
Revenues
Revenue from contract with customer, including assessed tax		28,707,000
Revenue from Reimbursement of Infrastructure Costs | Calculated under Revenue Guidance in Effect before Topic 606
Revenues
Revenue from contract with customer, including assessed tax		320,000
Impact Fee and Mitigation Credit Sales
Revenues
Revenue from contract with customer, including assessed tax	116,000
Impact Fee and Mitigation Credit Sales | Calculated under Revenue Guidance in Effect before Topic 606
Revenues
Revenue from contract with customer, including assessed tax		216,000
Subsurface Lease Revenue
Revenues
Lease Revenue	199,000	199,000
Subsurface Revenue - Other
Revenues
Revenue from contract with customer, including assessed tax	547,000
Subsurface Revenue - Other | Calculated under Revenue Guidance in Effect before Topic 606
Revenues
Revenue from contract with customer, including assessed tax		32,000
Golf Operations
Revenues
Revenue from contract with customer, including assessed tax	1,355,000
Golf Operations | Calculated under Revenue Guidance in Effect before Topic 606
Revenues
Revenue from contract with customer, including assessed tax		1,475,000
Timber Sales Revenue | Calculated under Revenue Guidance in Effect before Topic 606
Revenues
Revenue from contract with customer, including assessed tax		143,000
Interest and Other Revenue
Revenues
Revenue from contract with customer, including assessed tax	27,000
Interest and Other Revenue | Calculated under Revenue Guidance in Effect before Topic 606
Revenues
Revenue from contract with customer, including assessed tax		8,000
Income Properties
Revenues
Lease Revenue	9,179,000	7,065,000
Lease Incentive Amortization	(76,000)
Total Revenues	9,205,727	7,073,240
Income Properties | Lease Revenue - Base Rent
Revenues
Lease Revenue	7,422,000	5,554,000
Income Properties | Lease Revenue - CAM
Revenues
Lease Revenue	614,000	499,000
Income Properties | Lease Revenue - Reimbursements
Revenues
Lease Revenue	565,000	420,000
Income Properties | Lease Revenue - Billboards
Revenues
Lease Revenue	64,000	61,000
Income Properties | Above / Below Market Lease Accretion
Revenues
Lease Revenue	580,000	531,000
Income Properties | Contributed Leased Assets Accretion
Revenues
Lease Revenue	10,000
Income Properties | Interest and Other Revenue
Revenues
Revenue from contract with customer, including assessed tax	27,000
Income Properties | Interest and Other Revenue | Calculated under Revenue Guidance in Effect before Topic 606
Revenues
Revenue from contract with customer, including assessed tax		8,000
Commercial Loan Investments
Revenues
Interest from Commercial Loan Investments	301,000	537,000
Total Revenues	300,999	536,489
Real Estate Operations
Revenues
Lease Revenue	199,000	199,000
Total Revenues	13,979,330	29,474,460
Real Estate Operations | Land
Revenues
Revenue from contract with customer, including assessed tax	13,117,000
Real Estate Operations | Land | Calculated under Revenue Guidance in Effect before Topic 606
Revenues
Revenue from contract with customer, including assessed tax		28,707,000
Real Estate Operations | Revenue from Reimbursement of Infrastructure Costs | Calculated under Revenue Guidance in Effect before Topic 606
Revenues
Revenue from contract with customer, including assessed tax		320,000
Real Estate Operations | Impact Fee and Mitigation Credit Sales
Revenues
Revenue from contract with customer, including assessed tax	116,000
Real Estate Operations | Impact Fee and Mitigation Credit Sales | Calculated under Revenue Guidance in Effect before Topic 606
Revenues
Revenue from contract with customer, including assessed tax		216,000
Real Estate Operations | Subsurface Lease Revenue
Revenues
Lease Revenue	199,000	199,000
Real Estate Operations | Subsurface Revenue - Other
Revenues
Revenue from contract with customer, including assessed tax	547,000
Real Estate Operations | Subsurface Revenue - Other | Calculated under Revenue Guidance in Effect before Topic 606
Revenues
Revenue from contract with customer, including assessed tax		32,000
Golf Operations
Revenues
Total Revenues	1,354,356	1,474,944
Golf Operations | Golf Operations
Revenues
Revenue from contract with customer, including assessed tax	1,355,000
Golf Operations | Golf Operations | Calculated under Revenue Guidance in Effect before Topic 606
Revenues
Revenue from contract with customer, including assessed tax		1,475,000
Agriculture and Other Income
Revenues
Lease Revenue	11,000	11,000
Total Revenues	11,187	154,151
Agriculture and Other Income | Lease Revenue - Base Rent
Revenues
Lease Revenue	$ 11,000	11,000
Agriculture and Other Income | Timber Sales Revenue | Calculated under Revenue Guidance in Effect before Topic 606
Revenues
Revenue from contract with customer, including assessed tax		$ 143,000