Fair Value of Investments - Schedule of Changes in Fair Value of Level 3 Investments (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 4,382,413	$ 3,298,961	$ 4,174,054	$ 3,080,569
Purchases and Drawdowns	538,892	367,790	953,542	683,023
Sales and Paydowns	(242,509)	(161,034)	(461,402)	(262,572)
Other	8,369	7,472	16,817	13,534
Ending balance	4,685,649	3,512,536	4,685,649	3,512,536
Change in Unrealized Appreciation/(Depreciation) for Level 3 Assets Still Held	(434)	(759)	4	(460)
Investments \| Income Statement Location [Axis]: us-gaap:DebtAndEquitySecuritiesRealizedGainLoss
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Gains (losses) included in earnings	1,006	2	(299)	50
Investments \| Income Statement Location [Axis]: us-gaap:DebtAndEquitySecuritiesUnrealizedGainLoss
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Gains (losses) included in earnings	(2,522)	(655)	2,937	(2,068)
First lien senior secured debt
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	4,382,354	3,298,945	4,173,995	3,080,554
Purchases and Drawdowns	538,892	367,790	953,542	683,023
Sales and Paydowns	(242,509)	(161,034)	(461,402)	(262,572)
Other	8,368	7,472	16,815	13,534
Ending balance	4,685,584	3,512,520	4,685,584	3,512,520
Change in Unrealized Appreciation/(Depreciation) for Level 3 Assets Still Held	(439)	(759)	0	(461)
First lien senior secured debt \| Income Statement Location [Axis]: us-gaap:DebtAndEquitySecuritiesRealizedGainLoss
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Gains (losses) included in earnings	1,006	2	(299)	50
First lien senior secured debt \| Income Statement Location [Axis]: us-gaap:DebtAndEquitySecuritiesUnrealizedGainLoss
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Gains (losses) included in earnings	(2,527)	(655)	2,933	(2,069)
Sponsor subordinated note
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	59	16	59	15
Purchases and Drawdowns	0	0		0
Sales and Paydowns	0	0	0	0
Other	1	0	2	0
Ending balance	65	16	65	16
Change in Unrealized Appreciation/(Depreciation) for Level 3 Assets Still Held	5	0	4	1
Sponsor subordinated note \| Income Statement Location [Axis]: us-gaap:DebtAndEquitySecuritiesRealizedGainLoss
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Gains (losses) included in earnings	0	0	0	0
Sponsor subordinated note \| Income Statement Location [Axis]: us-gaap:DebtAndEquitySecuritiesUnrealizedGainLoss
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Gains (losses) included in earnings	$ 5	$ 0	$ 4	$ 1

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Other Increase (Decrease)

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- Definition

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales and Settlements

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Amount of unrealized gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3) and still held.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).

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- Definition

Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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