BUSINESS SEGMENT DATA - Summary of Operations in Different Segments (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business segment data
Total Revenues	$ 11,963,117	$ 11,329,979	$ 10,688,831	$ 10,959,319	$ 12,040,174	$ 10,443,476	$ 10,805,062	$ 10,369,176	$ 44,941,246	$ 43,657,888	$ 38,650,570
Operating Income	4,078,876	5,484,975	14,632,126	10,002,714	2,383,124	2,769,587	20,846,836	5,385,651	34,198,691	31,385,198	7,744,993
Gain on Disposition of Assets	1,108,269	2,187,332	11,811,907	6,869,957			18,384,808	3,650,858	21,977,465	22,035,666	38
Depreciation and Amortization	4,089,568	4,286,836	4,074,587	3,346,287	4,452,647	3,756,507	3,755,546	3,796,823	15,797,278	15,761,523	12,314,700
Identifiable Assets	703,286,203				556,329,872				703,286,203	556,329,872
Operating Segments
Business segment data
Operating Income									34,198,691	31,385,199	7,744,993
Gain on Disposition of Assets									21,977,465	22,035,666	38
Capital Expenditures									187,525,624	113,764,212	97,627,672
General and Corporate Expense
Business segment data
Operating Income									(25,615,353)	(25,546,893)	(22,567,310)
Income Properties
Business segment data
Total Revenues	10,594,870	10,260,831	10,375,295	10,724,418	11,728,550	9,360,155	9,781,299	9,205,727	41,955,414	40,075,731	31,406,930
Depreciation and Amortization									15,774,228	15,728,095	12,272,265
Identifiable Assets	464,285,272				492,093,615				464,285,272	492,093,615
Income Properties | Operating Segments
Business segment data
Operating Income									34,955,413	31,905,648	24,489,187
Capital Expenditures									166,683,689	108,996,747	92,125,062
Management Services
Business segment data
Total Revenues	304,553								304,553
Identifiable Assets	0				0				0	0
Management Services | Operating Segments
Business segment data
Operating Income									304,553
Commercial Loan Investments
Business segment data
Total Revenues	920,691	855,559	52,765			41,262	273,467	300,999	1,829,015	615,728	2,052,689
Identifiable Assets	35,742,218								35,742,218
Commercial Loan Investments | Operating Segments
Business segment data
Operating Income									1,829,015	615,728	2,052,689
Capital Expenditures									18,046,450		3,000,000
Real Estate Operations
Business segment data
Total Revenues	143,003	$ 213,589	$ 260,771	$ 234,901	311,624	$ 1,042,059	$ 750,296	$ 862,450	852,264	2,966,429	5,190,951
Identifiable Assets	65,554,619				14,315,805				65,554,619	14,315,805
Real Estate Operations | Operating Segments
Business segment data
Operating Income									747,598	2,375,050	3,770,389
Capital Expenditures									2,791,137	4,658,956
Land Operations
Business segment data
Identifiable Assets	833,167				20,971,754				833,167	20,971,754
Golf Operations
Business segment data
Gain on Disposition of Assets	15,000
Identifiable Assets					4,462,477					4,462,477
Golf Operations | Operating Segments
Business segment data
Capital Expenditures										94,734	2,373,894
Corporate and Other
Business segment data
Depreciation and Amortization									23,050	33,428	42,435
Identifiable Assets	$ 136,870,927				$ 24,486,221				136,870,927	24,486,221
Corporate and Other | Operating Segments
Business segment data
Capital Expenditures									$ 4,348	$ 13,775	$ 128,716