SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Reconciliation of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($)		Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	[1]	$ 44,080,327	$ 11,375,960
Restricted cash	[1]	148,066,240	57,999,396
Total cash, cash equivalents and restricted cash		192,146,567	69,375,356	$ 24,269,054	$ 16,011,830
Hunt CRE 2018-FL2, Ltd
Cash and Cash Equivalents [Line Items]
Restricted cash		0	57,999,396
LFT CRE 2021-FL1
Cash and Cash Equivalents [Line Items]
Restricted cash		$ 148,066,240	$ 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 September 30, 2021 and December 31, 2020, assets of consolidated VIEs totaled $1,003,113,182 and $591,318,506, respectively and the liabilities of consolidated VIEs totaled $826,707,857 and $463,411,967 respectively. See Note 4 for further discussion.