RELATED-PARTY TRANSACTIONS AND ARRANGEMENTS (Schedule of Related Party Transactions) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Distribution and stockholder fees payable	$ 111,000	$ 188,000
Selling commissions | Advisors
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	23,501	540,706	$ 798,184
Dealer manager fees | Advisors
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	7,000	206,689	331,799
Distribution and stockholder servicing fees | Advisors
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	60,948	65,165	21,753
Organization and offering costs | Advisors
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	6,571	109,044	169,944
Acquisition fees and expenses | Advisors
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	0	0	330,000
Advisory fees | Advisors
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	0	0	60,565
Operating expenses | Advisors
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	0	0	50,000
Financing coordination fees | Advisors
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	$ 0	$ 0	$ 99,750