LAND AND SUBSURFACE INTERESTS - Other Real Estate Assets (Details) - USD ($)	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Land and development costs and subsurface interests
Impact fees	$ 79,000		$ 402,000
Mitigation credits	460,000		723,000
Impact Fee and Mitigation Credits	538,926		$ 1,125,269
Mitigation credits sold	1,000,000	$ 1,500,000
Gain on mitigation credits sold	$ 882,000	$ 1,200,000
Gain on mitigation credits sold (in dollars per share)	$ 0.12	$ 0.14
Cash payments received for impact fees	$ 251,000	$ 506,000
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