RENTAL PROPERTIES (Reconciliation) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Rental Properties
Balance, Beginning	$ 398,554,000	$ 337,902,411
Additions:
Buildings, improvements and other assets	3,240,408	62,267,137	$ 38,160,379
Balance before deductions	401,794,408	400,169,548	350,111,976
Deduct:
Write-offs of retired or disposed assets	3,164,615	1,615,548	12,209,565
Balance, Ending	398,629,793	398,554,000	337,902,411
Accumulated Depreciation
Balance, Beginning	120,190,012	107,391,148
Add:
Depreciation for the year	16,994,509	14,414,411	14,802,911
Total additions	137,184,521	121,805,559	119,600,714
Deduct:
Accumulated depreciation of retired or disposed assets	3,164,615	1,615,547	12,209,566
Balance, Ending	$ 134,019,906	$ 120,190,012	$ 107,391,148