RELATED PARTY TRANSACTIONS - Narrative (Details)	1 Months Ended													3 Months Ended		9 Months Ended
	Dec. 31, 2023 USD ($)	Nov. 30, 2023 USD ($)	Oct. 31, 2023 USD ($)	Sep. 30, 2023 USD ($)	Sep. 29, 2023 USD ($)	Apr. 30, 2023 USD ($)	Mar. 31, 2023	Nov. 30, 2022 USD ($)	Oct. 31, 2022 USD ($)	Aug. 31, 2022 USD ($)	Feb. 28, 2022 USD ($)	Dec. 31, 2021 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) loan	Sep. 30, 2022 USD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)	Jul. 31, 2021 USD ($)
Related Party Transaction [Line Items]
Incentive fees earned														$ 2,600,000	$ 2,900,000	$ 7,900,000	$ 9,300,000
Due from affiliate				$ 1,000,000										1,000,000		1,000,000			$ 0
Principal repayment of loans																49,953,251	32,227,904
Loan exit fee																1,100,000
Additional principal funded																51,757,225	$ 127,248,748
Subsequent Event
Related Party Transaction [Line Items]
Principal repayment of loans			$ 1,700,000
Loan exit fee			100,000
Mr. Bernard Berman | Managers
Related Party Transaction [Line Items]
Membership interest				3.00%
AFC Agent
Related Party Transaction [Line Items]
Proceeds from related exit fees																1,400,000
AFC Agent | Subsequent Event
Related Party Transaction [Line Items]
Principal repayment of loans			2,300,000
Proceeds from related exit fees			100,000
Commitments			53,200,000
Sub. of Private Co. G
Related Party Transaction [Line Items]
Interest expense					$ 800,000
Sub. of Private Co. G | Subsequent Event
Related Party Transaction [Line Items]
Interest expense	$ 1,000,000	$ 1,000,000	$ 1,000,000
Sub. of Public Co. H
Related Party Transaction [Line Items]
Commitments				$ 84,000,000										$ 84,000,000		$ 84,000,000
Decrease in loan commitment						$ 6,000,000
Additional principal funded						9,000,000
Related Party
Related Party Transaction [Line Items]
Percentage of base management fees				0.375%										0.375%		0.375%
Percentage of aggregate amount of any outside fees				50.00%										50.00%		50.00%
Amounts payable				$ 4,900,000										$ 4,900,000		$ 4,900,000			5,700,000
Affiliated Entity
Related Party Transaction [Line Items]
Due to affiliate				$ 19,700										$ 19,700		$ 19,700			$ 18,100
Number of co-invested loans held | loan																4
Affiliated Entity | Private Co. I
Related Party Transaction [Line Items]
Loan commitments																				$ 15,500,000
Portion of company sold																		0.66666
Commitments																		$ 3,800,000
Affiliated Entity | Private Co. I | AFC Institutional Fund, LLC
Related Party Transaction [Line Items]
Percentage of loan held				33.33%										33.33%		33.33%
Affiliated Entity | Private Co. A
Related Party Transaction [Line Items]
Loan commitments													$ 20,000,000
Increase in loan commitments								$ 7,100,000			$ 15,300,000	$ 20,000,000
Interest rate							13.00%
Principal repayment of loans																$ 34,700,000
Commitments				$ 54,700,000										$ 54,700,000		54,700,000
Affiliated Entity | Private Co. A | Flower Loan Holdco LLC
Related Party Transaction [Line Items]
Increase in loan commitments								1,400,000				2,500,000
Affiliated Entity | Private Co. A | The Company and third party lender
Related Party Transaction [Line Items]
Increase in loan commitments											16,300,000
Affiliated Entity | Private Co. A | Third party lender
Related Party Transaction [Line Items]
Increase in loan commitments								1,500,000			$ 1,000,000
Affiliated Entity | Private Co. A | The Company, Flower Loan Holdco LLC and third party lenders
Related Party Transaction [Line Items]
Increase in loan commitments								$ 10,000,000
Affiliated Entity | Private Co. A | Lenders including the Company
Related Party Transaction [Line Items]
Principal repayment of loans																48,200,000
Affiliated Entity | Sub. of Private Co. G
Related Party Transaction [Line Items]
Loan commitments				73,500,000										73,500,000		73,500,000
Increase in loan commitments										$ 8,100,000			43,400,000
Commitments				80,600,000										80,600,000		80,600,000
Affiliated Entity | Sub. of Private Co. G | The Company and A BDC Warehouse, LLC
Related Party Transaction [Line Items]
Increase in loan commitments													53,400,000
Affiliated Entity | Sub. of Private Co. G | A BDC Warehouse, LLC
Related Party Transaction [Line Items]
Increase in loan commitments													$ 10,000,000
Affiliated Entity | Sub. of Public Co. H
Related Party Transaction [Line Items]
Loan commitments												60,000,000
Increase in loan commitments									$ 30,000,000
Commitments				$ 84,000,000										$ 84,000,000		$ 84,000,000
Affiliated Entity | Sub. of Public Co. H | Third party lender
Related Party Transaction [Line Items]
Loan commitments												30,000,000
Increase in loan commitments									15,000,000
Affiliated Entity | Sub. of Public Co. H | The Company, Predecessor in Interest to AFC Institutional Fund LLC and third party lenders
Related Party Transaction [Line Items]
Loan commitments												100,000,000
Increase in loan commitments						$ 10,000,000			50,000,000
Affiliated Entity | Sub. of Public Co. H | Predecessor in Interest To AFC Institutional Fund LLC
Related Party Transaction [Line Items]
Loan commitments												$ 10,000,000
Increase in loan commitments									$ 5,000,000