COMMERCIAL MORTGAGE LOANS HELD-FOR-INVESTMENT - Summary of Commercial Loan Risk Ratings (Details)	3 Months Ended			12 Months Ended
	Mar. 31, 2021 USD ($) mortgage_loan		Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($) mortgage_loan
Financing Receivable, Credit Quality Indicator [Line Items]
Commercial mortgage loans held-for-investment, at amortized cost	$ 484,165,249	[1]		$ 547,345,334
Average risk rating, moderate	2.7			3.1
Principal payments from commercial mortgage loans held-for-investment	$ 98,068,085		$ 34,507,879
Purchase of commercial loans held for investment	$ 34,888,000		$ 38,613,756
Commercial real estate portfolio segment
Financing Receivable, Credit Quality Indicator [Line Items]
Number of Loans | mortgage_loan	34			40
Unpaid Principal Balance	$ 484,165,249			$ 547,345,334
Commercial mortgage loans held-for-investment, at amortized cost	484,165,249			$ 547,345,334
Principal payments from commercial mortgage loans held-for-investment	98,068,085
Purchase of commercial loans held for investment	$ 34,888,000
Commercial real estate portfolio segment | Risk rating, 1
Financing Receivable, Credit Quality Indicator [Line Items]
Number of Loans | mortgage_loan	0			0
Unpaid Principal Balance	$ 0			$ 0
Commercial mortgage loans held-for-investment, at amortized cost	$ 0			$ 0
Commercial real estate portfolio segment | Risk rating, 2
Financing Receivable, Credit Quality Indicator [Line Items]
Number of Loans | mortgage_loan	10			14
Unpaid Principal Balance	$ 149,871,667			$ 168,401,366
Commercial mortgage loans held-for-investment, at amortized cost	149,871,667			$ 168,401,366
Purchase of commercial loans held for investment	$ 34,900,000
Commercial real estate portfolio segment | Risk rating, 3
Financing Receivable, Credit Quality Indicator [Line Items]
Number of Loans | mortgage_loan	21			20
Unpaid Principal Balance	$ 293,534,594			$ 309,726,343
Commercial mortgage loans held-for-investment, at amortized cost	$ 293,534,594			$ 309,726,343
Average risk rating, percentage	91.60%			84.40%
Transition of commercial loans from a risk rating of 4 to a risk rating of 3	$ 31,100,000
Commercial real estate portfolio segment | Risk rating, 4
Financing Receivable, Credit Quality Indicator [Line Items]
Number of Loans | mortgage_loan	3			6
Unpaid Principal Balance	$ 40,758,988			$ 69,217,625
Commercial mortgage loans held-for-investment, at amortized cost	40,758,988			$ 69,217,625
Principal payments from commercial mortgage loans held-for-investment	$ 16,700,000
Commercial real estate portfolio segment | Risk rating, 5
Financing Receivable, Credit Quality Indicator [Line Items]
Number of Loans | mortgage_loan	0			0
Unpaid Principal Balance	$ 0			$ 0
Commercial mortgage loans held-for-investment, at amortized cost	$ 0			$ 0

[1] Our consolidated balance sheets include assets and liabilities of consolidated variable interest entities ("VIEs") as the Company was the primary beneficiary of these VIEs. As of March 31, 2021 and December 31, 2020, assets of consolidated VIEs related to Hunt CRE 2017-F1, Ltd. and Hunt CRE 2018-FL2, Ltd. totaled $537,399,673 and $591,318,506, respectively and the liabilities of consolidated VIEs related to Hunt CRE 2017-FL1, Ltd. and Hunt CRE 2018-FL2, Ltd totaled $409,716,943 and $463,411,967 respectively. See Note 4 for further discussion.