RESIDENTIAL MORTGAGE LOAN SECURITIZATION TRUSTS - Narrative (Details) - Residential mortgage loans - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Investment in Non-Agency RMBS, carrying value	$ 5,158,318	$ 5,413,720
Residential mortgage loans held in securitization trust, unpaid balance	112,945,716	118,884,113
Residential mortgage loan securitized debt obligation, unpaid principal balance	$ 112,945,716	$ 118,884,113