USE OF SPECIAL PURPOSE ENTITIES AND VARIABLE INTEREST ENTITIES - Summary of Loan and Borrowing Characteristics (Details)		3 Months Ended	12 Months Ended
		Mar. 31, 2022 USD ($) mortgage_loan contract insturment	Dec. 31, 2021 USD ($) insturment contract mortgage_loan
Variable Interest Entity [Line Items]
Collateralized loan obligations	[1]	$ 827,405,880	$ 826,782,543
Commercial real estate portfolio segment
Variable Interest Entity [Line Items]
Collateral (loan investments) (Count) | mortgage_loan		71	66
Carrying Value		$ 1,077,516,319	$ 1,001,825,294
LFT CRE 2021-FL1, Ltd.
Variable Interest Entity [Line Items]
Financings provided, (Count) | insturment		1	1
Collateralized loan obligations		$ 827,405,880	$ 826,782,543
LFT CRE 2021-FL1, Ltd. | London Interbank Offered Rate (LIBOR)
Variable Interest Entity [Line Items]
Wtd. Avg. Yield		3.34%	3.42%
Wtd. Avg. Yield		1.43%	1.43%
LFT CRE 2021-FL1, Ltd. | Commercial real estate portfolio segment
Variable Interest Entity [Line Items]
Collateral (loan investments) (Count) | contract		64	64
Principal Value | LFT CRE 2021-FL1, Ltd.
Variable Interest Entity [Line Items]
Carrying Value		$ 998,657,267	$ 974,069,994
Collateralized loan obligations		833,750,000	83,375,000
Carrying Value | LFT CRE 2021-FL1, Ltd.
Variable Interest Entity [Line Items]
Carrying Value		998,667,789	974,025,294
Collateralized loan obligations		827,405,880	826,782,543
Debt issuance costs		$ 6,344,120	$ 6,967,457

[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.