BUSINESS SEGMENT DATA - Summary of Operations in Different Segments (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Business segment data
Revenues	$ 24,851,599	$ 38,713,284
Operating Income	16,986,842	22,849,411
Depreciation and Amortization	3,900,379	2,762,575
Identifiable Assets	484,443,604		$ 466,130,378
Operating Segments
Business segment data
Capital Expenditures	30,030,461	23,557,357
General and Corporate Expense
Business segment data
Operating Income	(3,073,069)	(3,756,196)
Income Properties
Business segment data
Revenues	9,205,727	7,073,240
Depreciation and Amortization	3,787,415	2,686,312
Identifiable Assets	422,321,016		388,602,721
Income Properties | Operating Segments
Business segment data
Operating Income	7,336,698	5,661,527
Capital Expenditures	27,915,262	21,937,532
Commercial Loan Investments
Business segment data
Revenues	300,999	536,489
Identifiable Assets	11,979,758		11,963,777
Commercial Loan Investments | Operating Segments
Business segment data
Operating Income	300,999	536,489
Real Estate Operations
Business segment data
Revenues	13,979,330	29,474,460
Identifiable Assets	33,635,025		43,296,528
Real Estate Operations | Operating Segments
Business segment data
Operating Income	12,443,668	20,317,611
Capital Expenditures	2,111,983
Golf Operations
Business segment data
Revenues	1,354,356	1,474,944
Depreciation and Amortization	103,556	65,367
Identifiable Assets	6,243,858		6,262,634
Golf Operations | Operating Segments
Business segment data
Operating Income	(27,469)	(23,734)
Capital Expenditures	2,663	1,607,742
Agriculture and Other Income
Business segment data
Revenues	11,187	154,151
Depreciation and Amortization	9,408	10,896
Identifiable Assets	10,263,947		$ 16,004,718
Agriculture and Other Income | Operating Segments
Business segment data
Operating Income	6,015	113,714
Capital Expenditures	$ 553	$ 12,083