COMMERCIAL MORTGAGE LOANS HELD-FOR-INVESTMENT - Additional Information (Details)			1 Months Ended	3 Months Ended				6 Months Ended		9 Months Ended			12 Months Ended
		Nov. 25, 2023 USD ($)	Feb. 28, 2023 USD ($)	Sep. 30, 2024 USD ($) loan		Mar. 31, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) loan		Sep. 30, 2024 USD ($) loan		Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($) loan		Dec. 31, 2022 USD ($)
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, allowance for credit loss, period increase (decrease)										$ 300,000
Loans held for investment	[1]			$ 9,515,493				$ 9,515,493		9,515,493			$ 6,059,006
Principal repayments										247,009,674		$ 203,425,029
Sale of loans			$ 6,000,000
Reserve for impaired loan							$ 4,300,000								$ 4,300,000
Commercial mortgage loans held-for-investment, at amortized cost				1,191,183,049	[1]			1,191,183,049	[1]	1,191,183,049	[1]		1,389,940,203	[1]	$ 1,076,148,186
Commercial Real Estate Portfolio Segment
Financing Receivable, Credit Quality Indicator [Line Items]
Principal repayments										247,009,674
Commercial mortgage loans held-for-investment, at amortized cost				1,195,799,230				1,195,799,230		1,195,799,230			1,397,385,160
Commercial Real Estate Portfolio Segment | Risk rating, 5
Financing Receivable, Credit Quality Indicator [Line Items]
Transition of commercial loans held for sale to a risk rating two steps higher										17,300,000
Commercial mortgage loans held-for-investment, at amortized cost				$ 83,768,210				$ 83,768,210		$ 83,768,210			45,670,764
Office Building
Financing Receivable, Credit Quality Indicator [Line Items]
Impaired unpaid principal value			$ 10,300,000
Multifamily | LFT CRE 2021-FL1, Ltd.
Financing Receivable, Credit Quality Indicator [Line Items]
Proceeds from collection of finance receivables													3,600,000
Multifamily | Risk rating, 5 | LFT CRE 2021-FL1, Ltd.
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, nonaccrual, interest income													$ 500,000
Basis spread on variable rate (basis points)										3.27%			4.00%
Multifamily | Commercial Real Estate Portfolio Segment | Risk rating, 5
Financing Receivable, Credit Quality Indicator [Line Items]
Financing receivable, allowance for credit loss, recovery						$ 2,500,000
Multifamily | Brooklyn, NY | Commercial Real Estate Portfolio Segment | Risk Level, Imminent Maturity Default Risk
Financing Receivable, Credit Quality Indicator [Line Items]
Number of impaired office loans | loan				1				1		1
Transition of commercial loans held for sale to a risk rating two steps higher										$ 17,300,000
Recognized interest on loan				$ 400,000
Multifamily | Augusta, GA | Commercial Real Estate Portfolio Segment | Risk Level, Monetary Default Default Risk
Financing Receivable, Credit Quality Indicator [Line Items]
Transition of commercial loans held for sale to a risk rating two steps higher										20,300,000
Recognized interest on loan				$ 700,000				$ 1,200,000
Multifamily | Philadelphia, PA | Commercial Real Estate Portfolio Segment | Risk Level, Monetary Default Default Risk
Financing Receivable, Credit Quality Indicator [Line Items]
Transition of commercial loans held for sale to a risk rating two steps higher										15,000,000
Transition of commercial loans held for sale to a risk rating allowance after analysis two steps higher										900,000
Principal repayments										300,000
Multifamily | Dallas, TX | Commercial Real Estate Portfolio Segment | Risk Level, Monetary Default Default Risk
Financing Receivable, Credit Quality Indicator [Line Items]
Transition of commercial loans held for sale to a risk rating two steps higher										$ 31,600,000
Multifamily | Columbus Ohio | Commercial Real Estate Portfolio Segment | Risk rating, 5
Financing Receivable, Credit Quality Indicator [Line Items]
Number of impaired office loans | loan													1
Transition of commercial loans held for sale to a risk rating two steps higher													$ 12,800,000
Financing receivable, loan in process													$ 8,900,000
Insurance recoveries		$ 5,000,000				13,500,000
Insurance recoveries applied to carrying value		3,100,000
Insurance recoveries applied to tenant settlement payable		$ 1,900,000
Commercial mortgage loans held-for-investment, at amortized cost						$ 0
Multifamily | Virginia | Commercial Real Estate Portfolio Segment | Risk rating, 5
Financing Receivable, Credit Quality Indicator [Line Items]
Number of impaired office loans | loan													1
Transition of commercial loans held for sale to a risk rating two steps higher													$ 36,800,000
Multi-Family Property One | Augusta, GA | Commercial Real Estate Portfolio Segment | Risk Level, Monetary Default Default Risk
Financing Receivable, Credit Quality Indicator [Line Items]
Number of impaired office loans | loan				1				1		1
Multi-Family Property One | Philadelphia, PA | Commercial Real Estate Portfolio Segment | Risk Level, Monetary Default Default Risk
Financing Receivable, Credit Quality Indicator [Line Items]
Number of impaired office loans | loan				1				1		1
Multi-Family Property One | Dallas, TX | Commercial Real Estate Portfolio Segment | Risk Level, Monetary Default Default Risk
Financing Receivable, Credit Quality Indicator [Line Items]
Number of impaired office loans | loan				1				1		1
Multi-Family Property Two | Augusta, GA | Commercial Real Estate Portfolio Segment | Risk Level, Monetary Default Default Risk
Financing Receivable, Credit Quality Indicator [Line Items]
Number of impaired office loans | loan				2				2		2
Multi-Family Property Two | Philadelphia, PA | Commercial Real Estate Portfolio Segment | Risk Level, Monetary Default Default Risk
Financing Receivable, Credit Quality Indicator [Line Items]
Number of impaired office loans | loan				2				2		2

[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, 2024 and December 31, 2023, assets of consolidated VIEs totaled $1,187,880,140 and $1,384,136,334, respectively and the liabilities of consolidated VIEs totaled $958,170,808 and $1,150,207,290 respectively. See Note 4 for further discussion.