LAND AND SUBSURFACE INTERESTS - Real Estate Operations Revenues (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues
Total Revenues	$ 13,833,185	$ 22,837,783	$ 38,684,784	$ 61,551,067
Real Estate Operations
Revenues
Subsurface Revenue	280,000	222,000	1,026,000	453,000
Total Revenues	2,484,314	13,257,355	16,463,644	42,731,815
Land
Revenues
Revenue from contract with customer, including assessed tax	1,734,000	10,858,000	14,851,000	39,564,000
Land | Real Estate Operations
Revenues
Revenue from contract with customer, including assessed tax	1,734,000	10,858,000	14,851,000	39,564,000
Revenue from Reimbursement of Infrastructure Costs
Revenues
Revenue from contract with customer, including assessed tax		955,000		1,276,000
Revenue from Reimbursement of Infrastructure Costs | Real Estate Operations
Revenues
Revenue from contract with customer, including assessed tax		955,000		1,276,000
Impact Fee and Mitigation Credit Sales
Revenues
Revenue from contract with customer, including assessed tax	470,000	1,222,000	586,000	1,439,000
Impact Fee and Mitigation Credit Sales | Real Estate Operations
Revenues
Revenue from contract with customer, including assessed tax	$ 470,000	$ 1,222,000	$ 586,000	$ 1,439,000