LAND AND SUBSURFACE INTERESTS - Other Real Estate Assets (Details) - USD ($)	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Land and development costs and subsurface interests
Impact fees	$ 199,000		$ 402,000
Mitigation credits	526,000		723,000
Impact Fee and Mitigation Credits	725,236		$ 1,125,269
Mitigation credits sold	455,000	$ 1,100,000
Gain on mitigation credits sold	$ 403,000	$ 932,000
Gain on mitigation credits sold (in dollars per share)	$ 0.05	$ 0.10
Cash payments received for impact fees	$ 131,000	$ 291,000
LandShark Bar and Grill
Land and development costs and subsurface interests
Cash payments received for impact fees	72,000
Real Estate Operations | Buc'ees - East of I-95
Land and development costs and subsurface interests
Mitigation credits transferred	$ 124,000