SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) - USD ($)		3 Months Ended	6 Months Ended	9 Months Ended
	Feb. 14, 2019	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jan. 15, 2019	Dec. 31, 2018	Dec. 15, 2015
Debt and Equity Securities, FV-NI [Line Items]
Non-accrual status		$ 0		$ 0
Recognized impairment		0		0
Allowance for loan losses		0		0
Principal amount		40,250,000		40,250,000	$ 40,250,000
Deferred financing costs amortized		$ 1,017,419		$ 1,017,419
Common stock, shares authorized (in shares)		450,000,000		450,000,000	450,000,000
Common stock, par value (in dollars per share)		$ 0.01		$ 0.01	$ 0.01
Common stock, shares issued (in shares)		24,943,383		24,943,383	23,692,164
Common stock, shares outstanding (in shares)		24,943,383		24,943,383	23,692,164	24,943,383
Stock repurchase program, authorized amount									$ 10,000,000
Preferred stock, shares outstanding (in shares)								1,610,000
Preferred stock, dividend rate, percentage				8.75%
Preferred stock, liquidation preference (in dollars per share)								$ 25.00
Other Operating Income (Expense)
Debt and Equity Securities, FV-NI [Line Items]
Reclassification of deferred financing costs from other assets to other operating expenses		$ 624,816
Redeemable Preferred Stock
Debt and Equity Securities, FV-NI [Line Items]
Preferred stock, shares outstanding (in shares)	1,610,000
Preferred stock, dividend rate, percentage	8.75%
Preferred stock, liquidation preference (in dollars per share)	$ 25
Delayed Draw Facility | Credit Agreement
Debt and Equity Securities, FV-NI [Line Items]
Principal amount	$ 40,250,000	$ 40,250,000		$ 40,250,000			$ 40,250,000
Collateralized Loan Obligations
Debt and Equity Securities, FV-NI [Line Items]
Maximum exposure to loss from consolidated trusts			$ 124,046,671	$ 124,046,671