Fair Value of Investments - Significant Unobservable Inputs (Details) $ in Thousands	Mar. 31, 2025 USD ($)		Dec. 31, 2024 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value	$ 3,384,519	[1],[2]	$ 3,161,223	[3],[4]
Discounted cash flow and market comparable | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value	3,104,398		2,386,617
First lien senior secured debt
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value	3,298,945		3,080,554
First lien senior secured debt | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value	3,298,945		3,080,554
First lien senior secured debt | Discounted cash flow | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value	3,096,398		2,379,881
First lien senior secured debt | Market comparable | Level 3 | Forward Revenue multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value	1,377		1,483
First lien senior secured debt | Market comparable | Level 3 | LTM Revenue multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value	5,072		$ 2,048
Investments at fair value, measurement input			0.6
First lien senior secured debt | Market comparable | Level 3 | LTM EBITDA multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value	$ 1,535		$ 1,845
Investments at fair value, measurement input	14.0		14.3
First lien senior secured debt | Market comparable | Level 3 | Forward EBITDA multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value			$ 1,345
Investments at fair value, measurement input			8.4
First lien senior secured debt | Minimum | Discounted cash flow | Level 3 | Yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value, measurement input	0.087		0.093
First lien senior secured debt | Minimum | Market comparable | Level 3 | Forward Revenue multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value, measurement input	0.9		0.9
First lien senior secured debt | Minimum | Market comparable | Level 3 | LTM Revenue multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value, measurement input	0.5
First lien senior secured debt | Maximum | Discounted cash flow | Level 3 | Yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value, measurement input	0.663		0.563
First lien senior secured debt | Maximum | Market comparable | Level 3 | Forward Revenue multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value, measurement input	2.0		2.0
First lien senior secured debt | Maximum | Market comparable | Level 3 | LTM Revenue multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value, measurement input	0.8
First lien senior secured debt | Weighted Average | Discounted cash flow | Level 3 | Yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value, measurement input	0.105		0.109
First lien senior secured debt | Weighted Average | Market comparable | Level 3 | Forward Revenue multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value, measurement input	1.3		1.3
First lien senior secured debt | Weighted Average | Market comparable | Level 3 | LTM Revenue multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value, measurement input	0.6		0.6
First lien senior secured debt | Weighted Average | Market comparable | Level 3 | LTM EBITDA multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value, measurement input	14.0		14.3
First lien senior secured debt | Weighted Average | Market comparable | Level 3 | Forward EBITDA multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value, measurement input			8.4
Sponsor subordinated note
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value	$ 16		$ 15
Sponsor subordinated note | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value	16		15
Sponsor subordinated note | Market comparable | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value			$ 15
Sponsor subordinated note | Market comparable | Level 3 | LTM EBITDA multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value	$ 16
Investments at fair value, measurement input	7.6		7.6
Sponsor subordinated note | Weighted Average | Market comparable | Level 3 | LTM EBITDA multiple
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Investments at fair value, measurement input	7.6		7.6

[1] Unless otherwise indicated, all investments represent co-investments made with the Company’s affiliates in accordance with the terms of the exemptive relief that the Company received from the U.S. Securities and Exchange Commission. Refer to Note 6 for further information.

[2] Unless otherwise indicated, all investments are considered Level 3 investments.

[3] Unless otherwise indicated, all investments represent co-investments made with the Company’s affiliates in accordance with the terms of the exemptive relief that the Company received from the U.S. Securities and Exchange Commission. Refer to Note 6 for further information.

[4] Unless otherwise indicated, all investments are considered Level 3 investments.