BUSINESS SEGMENT DATA - Summary of Operations in Different Segments (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Business segment data
Revenues	$ 14,259,319	$ 23,497,243
Operating Income	11,723,612	17,117,867
Gain on Disposition of Assets	6,869,957	3,650,858
Depreciation and Amortization	3,346,287	3,796,823
Identifiable Assets	518,507,258		$ 556,329,872
Operating Segments
Business segment data
Operating Income	11,723,612	17,117,867
Capital Expenditures	930,575	30,030,461
General and Corporate Expense
Business segment data
Operating Income	(5,847,907)	(6,620,371)
Income Properties
Business segment data
Revenues	10,724,418	9,205,727
Depreciation and Amortization	3,339,856	3,787,415
Identifiable Assets	472,412,073		492,093,615
Income Properties | Operating Segments
Business segment data
Operating Income	8,791,930	7,336,698
Capital Expenditures	58,005	27,915,262
Commercial Loan Investments
Business segment data
Revenues		300,999
Commercial Loan Investments | Operating Segments
Business segment data
Operating Income		300,999
Real Estate Operations
Business segment data
Revenues	3,534,901	13,990,517
Identifiable Assets	35,045,459		35,287,559
Real Estate Operations | Operating Segments
Business segment data
Operating Income	1,909,632	12,449,683
Capital Expenditures	870,509	2,111,983
Golf Operations
Business segment data
Identifiable Assets	4,680,691		4,462,477
Golf Operations | Operating Segments
Business segment data
Capital Expenditures		2,663
Corporate and Other
Business segment data
Depreciation and Amortization	6,431	9,408
Identifiable Assets	6,369,035		$ 24,486,221
Corporate and Other | Operating Segments
Business segment data
Capital Expenditures	$ 2,061	$ 553