Fair Value Measurements - Summary of Changes in Fair Value of Financial Instruments for which Level 3 Inputs were used to Determine Fair Value (Details) - Level 3 - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, beginning of period/year	$ 2,725,934	$ 997,846	$ 1,358,933	$ 712,113
Purchase of investments (including PIK)	580,254	188,629	2,100,170	638,192
Proceeds from principal repayments and sales of investments	(38,025)	(66,458)	(268,913)	(136,660)
Amortization of premium/accretion of discount, net	2,707	670	7,001	2,550
Net realized gain (loss) on investments	479	539	3,426	67
Net change in unrealized appreciation (depreciation) on investments	2,709	7,373	15,123	22,837
Transfers out of Level 3	(122,132)	(29,626)	(46,886)	(140,126)
Transfers to Level 3	74,795		57,867
Fair value, end of period	3,226,721	1,098,973	3,226,721	1,098,973
Net change in unrealized appreciation (depreciation) on non-controlled/non-affiliated company investments	2,967	7,604	17,087	22,019
First Lien Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, beginning of period/year	2,537,818	839,286	1,200,165	494,159
Purchase of investments (including PIK)	577,906	188,440	2,071,367	635,499
Proceeds from principal repayments and sales of investments	(38,025)	(66,458)	(234,713)	(136,446)
Amortization of premium/accretion of discount, net	2,619	661	6,696	2,408
Net realized gain (loss) on investments	479	539	2,793	68
Net change in unrealized appreciation (depreciation) on investments	1,585	7,459	10,129	16,489
Transfers out of Level 3	(87,667)	(29,626)		(71,876)
Transfers to Level 3	74,795		13,073
Fair value, end of period	3,069,510	940,301	3,069,510	940,301
Net change in unrealized appreciation (depreciation) on non-controlled/non-affiliated company investments	1,842	7,690	11,978	15,671
Second Lien Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, beginning of period/year	130,214	132,740	130,876	195,687
Purchase of investments (including PIK)	92	92	277	181
Proceeds from principal repayments and sales of investments			(34,200)
Amortization of premium/accretion of discount, net	58	13	277	151
Net realized gain (loss) on investments			633
Net change in unrealized appreciation (depreciation) on investments	546	788	674	5,864
Transfers out of Level 3	(34,465)		(46,886)	(68,250)
Transfers to Level 3			44,794
Fair value, end of period	96,445	133,633	96,445	133,633
Net change in unrealized appreciation (depreciation) on non-controlled/non-affiliated company investments	547	788	789	5,864
Equity and Other Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, beginning of period/year	57,902		27,892
Purchase of investments (including PIK)	2,256		28,526
Amortization of premium/accretion of discount, net	30		28
Net change in unrealized appreciation (depreciation) on investments	578		4,320
Fair value, end of period	60,766		60,766
Net change in unrealized appreciation (depreciation) on non-controlled/non-affiliated company investments	$ 578		$ 4,320
Preferred Equity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, beginning of period/year		25,820		22,267
Purchase of investments (including PIK)		97		2,512
Proceeds from principal repayments and sales of investments				(214)
Amortization of premium/accretion of discount, net		(4)		(9)
Net realized gain (loss) on investments				(1)
Net change in unrealized appreciation (depreciation) on investments		(874)		484
Fair value, end of period		25,039		25,039
Net change in unrealized appreciation (depreciation) on non-controlled/non-affiliated company investments		$ (874)		$ 484