Fair Value Measurements - Valuation Techniques and Significant Unobservable Inputs used in Recurring Level 3 Fair Value Measurements of Assets and Liabilities (Details) $ in Thousands		Jun. 30, 2024 USD ($)		Dec. 31, 2023 USD ($)
Fair Value Measurements
Fair Value	[1]	$ 3,387,141	[2]	$ 2,528,167	[3]
Loans at fair value where valuation (unadjusted) is obtained from third-party pricing service		277,263		245,093
Senior secured loans
Fair Value Measurements
Fair Value		2,906,171		2,171,243
Unitranche secured loans
Fair Value Measurements
Fair Value		168,253		184,853
Junior secured loans
Fair Value Measurements
Fair Value		154,998		87,986
Equity securities
Fair Value Measurements
Fair Value		157,719		84,085
Level 3 | Total Level 3 Assets
Fair Value Measurements
Fair Value		3,109,712		2,283,051
Level 3 | Senior secured loans | EBITDA multiples | Discounted cash flow
Fair Value Measurements
Fair Value		$ 1,933,882		$ 1,351,324
Level 3 | Senior secured loans | EBITDA multiples | Discounted cash flow | Weighted Average Mean
Fair Value Measurements
Investments, measurement input		11.3		11.1
Level 3 | Senior secured loans | EBITDA multiples | Discounted cash flow | Minimum
Fair Value Measurements
Investments, measurement input		3.8		5.0
Level 3 | Senior secured loans | EBITDA multiples | Discounted cash flow | Maximum
Fair Value Measurements
Investments, measurement input		24.4		22.2
Level 3 | Senior secured loans | EBITDA multiples | Enterprise value
Fair Value Measurements
Fair Value		$ 11,214		$ 10,310
Level 3 | Senior secured loans | EBITDA multiples | Enterprise value | Weighted Average Mean
Fair Value Measurements
Investments, measurement input				7.4
Level 3 | Senior secured loans | EBITDA multiples | Enterprise value | Minimum
Fair Value Measurements
Investments, measurement input				5.3
Level 3 | Senior secured loans | EBITDA multiples | Enterprise value | Maximum
Fair Value Measurements
Investments, measurement input				8.3
Level 3 | Senior secured loans | EBITDA Market Yields | Discounted cash flow | Weighted Average Mean
Fair Value Measurements
Investments, measurement input		0.113		0.114
Level 3 | Senior secured loans | EBITDA Market Yields | Discounted cash flow | Minimum
Fair Value Measurements
Investments, measurement input		0.087		0.087
Level 3 | Senior secured loans | EBITDA Market Yields | Discounted cash flow | Maximum
Fair Value Measurements
Investments, measurement input		0.210		0.240
Level 3 | Senior secured loans | Revenue Market Yields | Discounted cash flow | Weighted Average Mean
Fair Value Measurements
Investments, measurement input		0.115		0.116
Level 3 | Senior secured loans | Revenue Market Yields | Discounted cash flow | Minimum
Fair Value Measurements
Investments, measurement input		0.093		0.090
Level 3 | Senior secured loans | Revenue Market Yields | Discounted cash flow | Maximum
Fair Value Measurements
Investments, measurement input		0.245		0.166
Level 3 | Senior secured loans | Probability weighting of alternative outcomes | Liquidation
Fair Value Measurements
Fair Value		$ 9,221		$ 9,618
Level 3 | Senior secured loans | Probability weighting of alternative outcomes | Liquidation | Weighted Average Mean
Fair Value Measurements
Investments, measurement input		0.911		0.950
Level 3 | Senior secured loans | Probability weighting of alternative outcomes | Liquidation | Minimum
Fair Value Measurements
Investments, measurement input		0.911		0.950
Level 3 | Senior secured loans | Probability weighting of alternative outcomes | Liquidation | Maximum
Fair Value Measurements
Investments, measurement input		0.911		0.950
Level 3 | Senior secured loans | Revenue multiples | Discounted cash flow
Fair Value Measurements
Fair Value		$ 711,503		$ 559,534
Level 3 | Senior secured loans | Revenue multiples | Discounted cash flow | Weighted Average Mean
Fair Value Measurements
Investments, measurement input		7.3		7.2
Level 3 | Senior secured loans | Revenue multiples | Discounted cash flow | Minimum
Fair Value Measurements
Investments, measurement input		0.8		0.7
Level 3 | Senior secured loans | Revenue multiples | Discounted cash flow | Maximum
Fair Value Measurements
Investments, measurement input		18.3		19.5
Level 3 | Senior secured loans | Revenue multiples | Enterprise value
Fair Value Measurements
Fair Value				$ 6,473
Level 3 | Senior secured loans | Revenue multiples | Enterprise value | Weighted Average Mean
Fair Value Measurements
Investments, measurement input		0.5		0.6
Level 3 | Senior secured loans | Revenue multiples | Enterprise value | Minimum
Fair Value Measurements
Investments, measurement input		0.4		0.5
Level 3 | Senior secured loans | Revenue multiples | Enterprise value | Maximum
Fair Value Measurements
Investments, measurement input		1.6		1.6
Level 3 | Unitranche secured loans | EBITDA multiples | Discounted cash flow
Fair Value Measurements
Fair Value		$ 134,246		$ 151,703
Level 3 | Unitranche secured loans | EBITDA multiples | Discounted cash flow | Weighted Average Mean
Fair Value Measurements
Investments, measurement input		10.4		10.5
Level 3 | Unitranche secured loans | EBITDA multiples | Discounted cash flow | Minimum
Fair Value Measurements
Investments, measurement input		7.3		7.3
Level 3 | Unitranche secured loans | EBITDA multiples | Discounted cash flow | Maximum
Fair Value Measurements
Investments, measurement input		14.5		14.8
Level 3 | Unitranche secured loans | EBITDA Market Yields | Discounted cash flow | Weighted Average Mean
Fair Value Measurements
Investments, measurement input		0.135		0.150
Level 3 | Unitranche secured loans | EBITDA Market Yields | Discounted cash flow | Minimum
Fair Value Measurements
Investments, measurement input		0.086		0.086
Level 3 | Unitranche secured loans | EBITDA Market Yields | Discounted cash flow | Maximum
Fair Value Measurements
Investments, measurement input		0.222		0.246
Level 3 | Unitranche secured loans | Revenue Market Yields | Discounted cash flow | Weighted Average Mean
Fair Value Measurements
Investments, measurement input		0.132		0.123
Level 3 | Unitranche secured loans | Revenue Market Yields | Discounted cash flow | Minimum
Fair Value Measurements
Investments, measurement input		0.123		0.119
Level 3 | Unitranche secured loans | Revenue Market Yields | Discounted cash flow | Maximum
Fair Value Measurements
Investments, measurement input		0.141		0.127
Level 3 | Unitranche secured loans | Revenue multiples | Discounted cash flow
Fair Value Measurements
Fair Value		$ 34,007		$ 33,150
Level 3 | Unitranche secured loans | Revenue multiples | Discounted cash flow | Weighted Average Mean
Fair Value Measurements
Investments, measurement input		9.2		9.4
Level 3 | Unitranche secured loans | Revenue multiples | Discounted cash flow | Minimum
Fair Value Measurements
Investments, measurement input		6.0		6.0
Level 3 | Unitranche secured loans | Revenue multiples | Discounted cash flow | Maximum
Fair Value Measurements
Investments, measurement input		12.5		12.8
Level 3 | Junior secured loans | EBITDA multiples | Discounted cash flow
Fair Value Measurements
Fair Value				$ 70,881
Level 3 | Junior secured loans | EBITDA multiples | Discounted cash flow | Weighted Average Mean
Fair Value Measurements
Investments, measurement input				13.5
Level 3 | Junior secured loans | EBITDA multiples | Discounted cash flow | Minimum
Fair Value Measurements
Investments, measurement input				13.5
Level 3 | Junior secured loans | EBITDA multiples | Discounted cash flow | Maximum
Fair Value Measurements
Investments, measurement input				13.5
Level 3 | Junior secured loans | Market yields | Discounted cash flow
Fair Value Measurements
Fair Value		$ 116,680
Level 3 | Junior secured loans | Market yields | Discounted cash flow | Weighted Average Mean
Fair Value Measurements
Investments, measurement input		0.141
Level 3 | Junior secured loans | Market yields | Discounted cash flow | Minimum
Fair Value Measurements
Investments, measurement input		0.118
Level 3 | Junior secured loans | Market yields | Discounted cash flow | Maximum
Fair Value Measurements
Investments, measurement input		0.173
Level 3 | Junior secured loans | EBITDA Market Yields | Discounted cash flow | Weighted Average Mean
Fair Value Measurements
Investments, measurement input				0.126
Level 3 | Junior secured loans | EBITDA Market Yields | Discounted cash flow | Minimum
Fair Value Measurements
Investments, measurement input				0.116
Level 3 | Junior secured loans | EBITDA Market Yields | Discounted cash flow | Maximum
Fair Value Measurements
Investments, measurement input				0.184
Level 3 | Junior secured loans | Revenue Market Yields | Discounted cash flow | Weighted Average Mean
Fair Value Measurements
Investments, measurement input		0.220		0.162
Level 3 | Junior secured loans | Revenue Market Yields | Discounted cash flow | Minimum
Fair Value Measurements
Investments, measurement input		0.220		0.162
Level 3 | Junior secured loans | Revenue Market Yields | Discounted cash flow | Maximum
Fair Value Measurements
Investments, measurement input		0.220		0.162
Level 3 | Junior secured loans | Revenue multiples | Discounted cash flow
Fair Value Measurements
Fair Value		$ 751		$ 348
Level 3 | Junior secured loans | Revenue multiples | Discounted cash flow | Weighted Average Mean
Fair Value Measurements
Investments, measurement input		1.0		0.9
Level 3 | Junior secured loans | Revenue multiples | Discounted cash flow | Minimum
Fair Value Measurements
Investments, measurement input		1.0		0.9
Level 3 | Junior secured loans | Revenue multiples | Discounted cash flow | Maximum
Fair Value Measurements
Investments, measurement input		1.0		0.9
Level 3 | Junior secured loans | Revenue multiples | Enterprise value
Fair Value Measurements
Fair Value		$ 3,153		$ 6,241
Level 3 | Junior secured loans | Revenue multiples | Enterprise value | Weighted Average Mean
Fair Value Measurements
Investments, measurement input		0.7		1.6
Level 3 | Junior secured loans | Revenue multiples | Enterprise value | Minimum
Fair Value Measurements
Investments, measurement input		0.3		1.6
Level 3 | Junior secured loans | Revenue multiples | Enterprise value | Maximum
Fair Value Measurements
Investments, measurement input		1.6		1.6
Level 3 | Equity securities | EBITDA multiples | Enterprise value
Fair Value Measurements
Fair Value		$ 99,521		$ 52,062
Level 3 | Equity securities | EBITDA multiples | Enterprise value | Weighted Average Mean
Fair Value Measurements
Investments, measurement input		11.3		10.7
Level 3 | Equity securities | EBITDA multiples | Enterprise value | Minimum
Fair Value Measurements
Investments, measurement input		3.8		6.3
Level 3 | Equity securities | EBITDA multiples | Enterprise value | Maximum
Fair Value Measurements
Investments, measurement input		21.5		20.5
Level 3 | Equity securities | Revenue multiples | Enterprise value
Fair Value Measurements
Fair Value		$ 52,082		$ 29,920
Level 3 | Equity securities | Revenue multiples | Enterprise value | Weighted Average Mean
Fair Value Measurements
Investments, measurement input		3.6		3.6
Level 3 | Equity securities | Revenue multiples | Enterprise value | Minimum
Fair Value Measurements
Investments, measurement input		0.4		0.5
Level 3 | Equity securities | Revenue multiples | Enterprise value | Maximum
Fair Value Measurements
Investments, measurement input		11.8		11.8
Level 3 | Equity securities | Volatility | Option pricing model
Fair Value Measurements
Fair Value		$ 3,452		$ 1,487
Level 3 | Equity securities | Volatility | Option pricing model | Weighted Average Mean
Fair Value Measurements
Investments, measurement input		0.470		0.596
Level 3 | Equity securities | Volatility | Option pricing model | Minimum
Fair Value Measurements
Investments, measurement input		0.250		0.350
Level 3 | Equity securities | Volatility | Option pricing model | Maximum
Fair Value Measurements
Investments, measurement input		0.725		0.740

[1] All of the Company’s investments are issued by eligible portfolio companies, as defined in the Investment Company Act of 1940, as amended, (the “1940 Act”), unless otherwise noted. All of the Company’s investments are issued by U.S. portfolio companies unless otherwise noted.

[2] Except as otherwise noted, because there is no readily available market value for these investments, the fair value of each of these investments is determined in good faith using significant unobservable inputs by the Valuation Designee. (See Note 4 in the accompanying notes to the consolidated financial statements).

[3] Except as otherwise noted, because there is no readily available market value for these investments, the fair value of each of these investments is determined in good faith using significant unobservable inputs by the Valuation Designee. (See Note 4 in the accompanying notes to the consolidated financial statements.)