SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) - USD ($)			3 Months Ended		12 Months Ended
	Apr. 12, 2019	Feb. 14, 2019	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Jan. 15, 2019	Dec. 15, 2015
Debt and Equity Securities, FV-NI [Line Items]
Maximum exposure to loss from consolidated trusts			$ 0			$ 4,762,149
Non-accrual status			0
Recognized impairment			0
Allowance for loan losses			0
Principal amount			40,250,000
Deferred financing costs amortized			970,545
Available for sale securities			0		$ 0
Outstanding repurchase agreements			$ 0		$ 0
Backstop deferred income, amortization period			5 years
Backstop guarantee, assumed prepayment rate (percentage)			15.00%
Common stock, shares authorized (in shares)			450,000,000		450,000,000
Common stock, par value (in dollars per share)			$ 0.01		$ 0.01
Common stock, shares issued (in shares)			23,687,664		23,687,664
Stock repurchase program, authorized amount								$ 10,000,000
Preferred stock, shares authorized (in shares)			50,000,000		50,000,000
Preferred stock, par value (in dollars per share)			$ 0.01		$ 0.01
Preferred stock, shares issued (in shares)			0		1,610,000
Common stock, shares outstanding (in shares)			23,687,664		23,687,664
Preferred stock, shares outstanding (in shares)			0		1,610,000
Preferred stock, dividend rate, percentage			8.75%	8.75%	8.75%
Preferred stock, liquidation preference (in dollars per share)					$ 25
Tax liability					$ 1,960,000
Credit Agreement | Delayed Draw Facility
Debt and Equity Securities, FV-NI [Line Items]
Principal amount		$ 40,250,000.00	$ 40,250,000.00				$ 40,250,000.00
Stock Repurchase Program
Debt and Equity Securities, FV-NI [Line Items]
Weighted average share price of common stock repurchased (in dollars per share)			$ 5.09
Number of shares repurchased (in shares)			126,856		126,856
Common stock repurchase activity (in shares)			0
Stock repurchase program, remaining authorized amount			$ 9,400,000
Collateralized Loan Obligations
Debt and Equity Securities, FV-NI [Line Items]
Maximum exposure to loss from consolidated trusts			$ 124,046,671
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
Subsequent Event | Internal Revenue Service (IRS)
Debt and Equity Securities, FV-NI [Line Items]
Income taxes, interest paid	$ 1,960,000