Debt - Schedule of Debt (Details) - USD ($)		Jun. 30, 2024	Dec. 31, 2023	Oct. 27, 2021	Mar. 28, 2016
Debt Instrument [Line Items]
Aggregate Principal Amount Committed		$ 1,181,600,000	$ 1,181,600,000
Drawn Amount	[1],[2]	887,837,000	851,921,000
Amount Available	[3]	293,763,000	329,679,000
SPV Asset Facility
Debt Instrument [Line Items]
Aggregate Principal Amount Committed		500,000,000	500,000,000		$ 500,000,000
Drawn Amount	[1],[2]	356,100,000	329,850,000
Amount Available	[3]	143,900,000	170,150,000
SMBC Corporate Revolving Facility
Debt Instrument [Line Items]
Aggregate Principal Amount Committed		385,000,000	385,000,000	$ 385,000,000
Drawn Amount	[1],[2]	235,137,000	225,471,000
Amount Available	[3]	149,863,000	159,529,000
Series 2021A Unsecured Notes
Debt Instrument [Line Items]
Aggregate Principal Amount Committed	[4]	135,000,000	135,000,000
Drawn Amount	[1],[2],[4]	135,000,000	135,000,000
FCRX Unsecured Notes
Debt Instrument [Line Items]
Aggregate Principal Amount Committed	[5]	111,600,000	111,600,000
Drawn Amount	[1],[2],[5]	111,600,000	111,600,000
Series 2023A Unsecured Notes
Debt Instrument [Line Items]
Aggregate Principal Amount Committed	[6]	50,000,000	50,000,000
Drawn Amount	[1],[2],[6]	$ 50,000,000	$ 50,000,000

[1] As of June 30, 2024 and December 31, 2023, the carrying amount of the Company’s outstanding debt approximated fair value unless otherwise noted.

[2] The amount presented excludes netting of deferred financing costs.

[3] The amount available is subject to any limitations related to the respective debt facilities’ borrowing bases and foreign currency translation adjustments.

[4] As of June 30, 2024 and December 31, 2023, the fair value of the Series 2021A Unsecured Notes was approximately $129,531 and $128,296, respectively.

[5] As of June 30, 2024 and December 31, 2023, the fair value of the FCRX Unsecured Notes was approximately $107,359 and $104,458.

[6] As of June 30, 2024 and December 31, 2023, the fair value of the Series 2023A Unsecured Notes was approximately $51,590 and $51,986.