Financing Arrangements - Narrative (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023	Jun. 15, 2019	Jun. 14, 2019
Debt Instrument [Line Items]
Asset coverage per ratio	183.00%		183.00%
Long term outstanding	$ 8,084		$ 8,223
Average outstanding amount	$ 8,149	$ 8,609
Weighted average interest rate	5.48%	5.22%
Effective interest rate percentage	5.49%	5.31%
Investment Advisory Agreement | FS/KKR Advisor, LLC
Debt Instrument [Line Items]
Asset coverage per ratio				150.00%	200.00%