Amount of fees and commissions from banking, advisory, brokerage, and securities underwriting activities. Activities include, but are not limited to, underwriting securities, private placements of securities, investment advisory and management services, merger and acquisition services, sale and servicing of mutual funds, and other related consulting fees.

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Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Structuring Fees
Related Party Transaction [Line Items]
Structuring fee revenue	$ 13	$ 29
Investment Advisory Agreement - Incentive Rate, Realized Capital Gains \| FS/KKR Advisor, LLC
Related Party Transaction [Line Items]
Incentive fee percentage	20.00%
Investment Advisory Agreement - Incentive Rate, Quarterly In Arrears Catch-up Threshold \| FS/KKR Advisor, LLC
Related Party Transaction [Line Items]
Incentive fee percentage	17.50%
Investment Advisory Agreement - Incentive Rate, Quarterly Catch-up Threshold \| FS/KKR Advisor, LLC
Related Party Transaction [Line Items]
Incentive fee percentage	1.75%
Investment Advisory Agreement - Incentive Rate, Annualized Hurdle Rate \| FS/KKR Advisor, LLC
Related Party Transaction [Line Items]
Incentive fee percentage	7.00%
Investment Advisory Agreement - Incentive Rate, Pre-Incentive Fee Net Investment Income Below Catch-Up Threshold \| FS/KKR Advisor, LLC
Related Party Transaction [Line Items]
Incentive fee percentage	2.12%
Investment Advisory Agreement - Incentive Rate, Annualized Catch-Up Threshold \| FS/KKR Advisor, LLC
Related Party Transaction [Line Items]
Incentive fee percentage	8.48%