Investments - Investment Portfolio at Cost and Fair Value (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2022		Dec. 31, 2021
Schedule of Investments [Line Items]
Cost	$ 50,175,620		$ 30,698,023
Fair Value	$ 48,959,003		$ 30,795,693
Investments At Fair Value | Investment Type Concentration Risk
Schedule of Investments [Line Items]
% of Total Investments at Fair Value	100.00%		100.00%
First lien debt
Schedule of Investments [Line Items]
Cost	$ 44,901,859	[1],[2]	$ 28,076,107	[3],[4]
Fair Value	$ 43,902,022	[2]	$ 28,143,451	[4]
First lien debt | Investments At Fair Value | Investment Type Concentration Risk
Schedule of Investments [Line Items]
% of Total Investments at Fair Value	89.67%		91.39%
Second lien debt
Schedule of Investments [Line Items]
Cost	$ 2,256,935	[1],[2]	$ 1,799,656	[4]
Fair Value	$ 2,111,420	[2]	$ 1,813,872	[4]
Second lien debt | Investments At Fair Value | Investment Type Concentration Risk
Schedule of Investments [Line Items]
% of Total Investments at Fair Value	4.31%		5.89%
Unsecured debt
Schedule of Investments [Line Items]
Cost	$ 21,432		$ 6,061
Fair Value	$ 17,370		$ 5,842
Unsecured debt | Investments At Fair Value | Investment Type Concentration Risk
Schedule of Investments [Line Items]
% of Total Investments at Fair Value	0.04%		0.02%
Structured Finance Investments
Schedule of Investments [Line Items]
Cost	$ 409,571	[1],[2]	$ 287,275	[3],[4]
Fair Value	$ 357,384	[2]	$ 286,610	[4]
Structured Finance Investments | Investments At Fair Value | Investment Type Concentration Risk
Schedule of Investments [Line Items]
% of Total Investments at Fair Value	0.73%		0.93%
Investment in joint venture
Schedule of Investments [Line Items]
Cost	$ 1,895,396		$ 0
Fair Value	$ 1,856,239		$ 0
Investment in joint venture | Investments At Fair Value | Investment Type Concentration Risk
Schedule of Investments [Line Items]
% of Total Investments at Fair Value	3.79%		0.00%
Equity investments
Schedule of Investments [Line Items]
Cost	$ 690,426		$ 528,924
Fair Value	$ 714,568		$ 545,918
Equity investments | Investments At Fair Value | Investment Type Concentration Risk
Schedule of Investments [Line Items]
% of Total Investments at Fair Value	1.46%		1.77%

[1] The cost represents the original cost adjusted for the amortization of discounts and premiums, as applicable, on debt investments using the effective interest method in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”).

[2] Unless otherwise indicated, issuers of debt and equity investments held by the Company (which such term “Company” shall include the Company’s consolidated subsidiaries for purposes of this Consolidated Schedule of Investments) are denominated in dollars. All debt investments are income producing unless otherwise indicated. All equity investments are non-income producing unless otherwise noted. Certain portfolio company investments are subject to contractual restrictions on sales. The total par amount is presented for debt investments and the number of shares or units owned is presented for equity investments. Each of the Company’s investments is pledged as collateral, under one or more of its credit facilities unless otherwise indicated.

[3] The cost represents the original cost adjusted for the amortization of discounts and premiums, as applicable, on debt investments using the effective interest method in accordance with U.S. GAAP.

[4] Unless otherwise indicated, issuers of debt and equity investments held by the Company are denominated in dollars. All debt investments are income producing unless otherwise indicated. All equity investments are non-income producing unless otherwise noted. Certain portfolio company investments are subject to contractual restrictions on sales. The total par amount is presented for debt investments and the number of shares or units owned is presented for equity investments. Each of the Company’s investments is pledged as collateral, under one or more of its credit facilities unless otherwise indicated.