BUSINESS SEGMENT DATA - Summary of Operations in Different Segments (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business segment data
Revenues	$ 33,227,164	$ 17,413,926	$ 12,550,267	$ 23,497,243	$ 16,041,186	$ 11,583,182	$ 21,454,270	$ 37,238,340	$ 86,688,600	$ 86,316,978	$ 65,884,467
Operating Income	20,157,408	4,378,080	21,840,017	17,117,867	6,058,862	4,330,634	8,154,135	20,711,986	63,493,372	39,255,617	37,982,344
Gain on Disposition of Assets			18,384,808	3,650,858	304	(266)			22,035,666	38	12,758,770
Depreciation and Amortization	4,452,647	3,756,507	3,755,546	3,796,823	3,433,913	3,063,211	3,120,368	2,697,208	15,761,523	12,314,700	7,929,343
Identifiable Assets	556,329,872				466,130,378				556,329,872	466,130,378
Operating Segments
Business segment data
Operating Income									63,493,372	39,255,617	37,982,344
Capital Expenditures									113,764,212	97,627,672	92,550,168
General and Corporate Expense
Business segment data
Operating Income									(25,546,893)	(22,567,310)	(20,407,950)
Income Properties
Business segment data
Revenues	11,728,550	9,360,155	9,781,299	9,205,727	8,840,425	7,928,258	7,565,007	7,073,240	40,075,731	31,406,930	25,092,484
Depreciation and Amortization									15,728,095	12,272,265	7,872,689
Identifiable Assets	492,093,615				388,602,721				492,093,615	388,602,721
Income Properties | Operating Segments
Business segment data
Operating Income									31,905,648	24,489,187	19,887,621
Capital Expenditures									108,996,747	92,125,062	92,434,774
Commercial Loan Investments
Business segment data
Revenues		41,262	273,467	300,999	325,240	637,801	553,159	536,489	615,728	2,052,689	2,588,235
Identifiable Assets					11,963,777					11,963,777
Commercial Loan Investments | Operating Segments
Business segment data
Operating Income									615,728	2,052,689	2,588,235
Capital Expenditures										3,000,000
Real Estate Operations
Business segment data
Revenues	21,498,614	$ 8,012,509	$ 2,495,501	$ 13,990,517	6,875,521	$ 3,017,123	$ 13,336,104	$ 29,628,611	45,997,141	52,857,359	38,203,748
Identifiable Assets	35,287,559				43,296,528				35,287,559	43,296,528
Real Estate Operations | Operating Segments
Business segment data
Operating Income									34,483,223	35,281,013	23,155,668
Capital Expenditures									4,658,956
Golf Operations
Business segment data
Identifiable Assets	4,462,477				6,262,634				4,462,477	6,262,634
Golf Operations | Operating Segments
Business segment data
Capital Expenditures									94,734	2,373,894	95,513
Agriculture and Other Income
Business segment data
Depreciation and Amortization									33,428	42,435	56,654
Identifiable Assets	$ 24,486,221				$ 16,004,718				24,486,221	16,004,718
Agriculture and Other Income | Operating Segments
Business segment data
Capital Expenditures									$ 13,775	$ 128,716	$ 19,881