SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) - USD ($)			3 Months Ended	12 Months Ended		25 Months Ended
		Mar. 08, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 15, 2015
Debt and Equity Securities, FV-NI [Line Items]
Available-for-sale securities				$ 0	$ 1,234,522,000	$ 1,234,522,000
Residential loans held in securitization trusts, at fair value	[1]			0	119,756,455	119,756,455
Nonaccrual status loans				0
AFS debt securities				0	1,290,825,648	1,290,825,648
Impairments on loans held-for-investments				0
Allowance for loan losses				0
Available-for-sale securities				$ 0	$ 1,290,825,648	$ 1,290,825,648
Backstop deferred income amortization period				5 years
Backstop guarantee, assumed prepayment rate				15.00%
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)				23,687,664	22,143,758	22,143,758
Common stock, shares outstanding (in shares)				23,687,664	22,143,758	22,143,758
Stock repurchase program, authorized amount									$ 10,000,000
Preferred stock, shares authorized (in shares)				50,000,000	50,000,000	50,000,000
Preferred stock, par value (in dollars per share)				$ 0.01	$ 0.01	$ 0.01
Preferred stock, shares issued (in shares)				1,610,000	1,610,000	1,610,000
Preferred stock, shares outstanding (in shares)				1,610,000	1,610,000	1,610,000
Accrued tax liability from REIT Testing				$ 1,960,000
Cash paid for interest				19,163,004	$ 14,477,370
Non Agency RMBS
Debt and Equity Securities, FV-NI [Line Items]
Maximum exposure to loss from consolidated trusts				4,762,149	27,108,818
Collateralized Loan Obligations
Debt and Equity Securities, FV-NI [Line Items]
Maximum exposure to loss from consolidated trusts				$ 124,046,671
Multi Family MBS
Debt and Equity Securities, FV-NI [Line Items]
Available-for-sale securities					$ 5,742,000	$ 5,742,000
Internal Revenue Service (IRS)
Debt and Equity Securities, FV-NI [Line Items]
Cash paid for interest			$ 2,010,000
Income taxes, interest provision							$ 1,860,000	$ 1,860,000
Income taxes, interest expense		$ 150,000	$ 150,000
Stock Repurchase Program
Debt and Equity Securities, FV-NI [Line Items]
Stock repurchase program, authorized amount									$ 10,000,000
Common stock shares repurchased (in shares)				0	126,856	126,856
Weighted average share price of common stock repurchased (in dollars per share)					$ 5.09	$ 5.09
Common stock shares repurchased (in shares)				$ 9,400,000
Residential mortgage loans
Debt and Equity Securities, FV-NI [Line Items]
Investment in Multi-Family MBS, carrying value				$ 0	$ 5,413,720	$ 5,413,720

[1] Our consolidated balance sheets include assets and liabilities of consolidated variable interest entities (“VIE's) as the Company is the primary beneficiary of these VIEs. As of December 31, 2018 and December 31, 2017, assets of consolidated VIEs totaled $24,357,335 and $1,255,404,335, respectively, and the liabilities of consolidated VIEs totaled $19,595,186 and $1,228,295,517, respectively