LAND AND SUBSURFACE INTERESTS - Real Estate Operations Revenues (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues
Total Revenues	$ 24,851,599	$ 38,713,284
Real Estate Operations
Revenues
Subsurface Revenue	746,000	231,000
Total Revenues	13,979,330	29,474,460
Land
Revenues
Revenue from contract with customer, including assessed tax	13,117,000
Land | Real Estate Operations
Revenues
Revenue from contract with customer, including assessed tax	13,117,000
Impact Fee and Mitigation Credit Sales
Revenues
Revenue from contract with customer, including assessed tax	116,000
Impact Fee and Mitigation Credit Sales | Real Estate Operations
Revenues
Revenue from contract with customer, including assessed tax	$ 116,000
Calculated under Revenue Guidance in Effect before Topic 606 | Land
Revenues
Revenue from contract with customer, including assessed tax		28,707,000
Calculated under Revenue Guidance in Effect before Topic 606 | Land | Real Estate Operations
Revenues
Revenue from contract with customer, including assessed tax		28,707,000
Calculated under Revenue Guidance in Effect before Topic 606 | Revenue from Reimbursement of Infrastructure Costs
Revenues
Revenue from contract with customer, including assessed tax		320,000
Calculated under Revenue Guidance in Effect before Topic 606 | Revenue from Reimbursement of Infrastructure Costs | Real Estate Operations
Revenues
Revenue from contract with customer, including assessed tax		320,000
Calculated under Revenue Guidance in Effect before Topic 606 | Impact Fee and Mitigation Credit Sales
Revenues
Revenue from contract with customer, including assessed tax		216,000
Calculated under Revenue Guidance in Effect before Topic 606 | Impact Fee and Mitigation Credit Sales | Real Estate Operations
Revenues
Revenue from contract with customer, including assessed tax		$ 216,000