COMMERCIAL MORTGAGE LOANS HELD-FOR-INVESTMENT - Loan Portfolio Activity (Details) - USD ($)		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Commercial Mortgage Loans Held-for-Investment
Balance at December 31, 2021	[1]	$ 1,001,825,294
Purchases and fundings		184,992,167	$ 34,888,000
Principal payments		(131,756,365)	(98,068,085)
Accretion of purchase discount		100,572	(207,767)
Amortization of purchase premium		(45,349)	$ 0
Balance at March 31, 2022	[1]	1,077,516,319
Commercial real estate portfolio segment
Commercial Mortgage Loans Held-for-Investment
Balance at December 31, 2021		1,001,825,294
Purchases and fundings		184,992,167
Principal payments		(109,356,365)
Accretion of purchase discount		100,572
Amortization of purchase premium		(45,349)
Balance at March 31, 2022		$ 1,077,516,319

[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, 2022 and December 31, 2021, assets of consolidated VIEs totaled $1,002,685,982 and $1,003,896,995, respectively and the liabilities of consolidated VIEs totaled $828,126,768 and $827,390,435 respectively. See Note 4 for further discussion.