Fair Value of Financial Instruments - Schedule of Roll Forward Level III (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Accretion of discount (amortization of premium)	$ 49	$ 43
Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at beginning of period	13,073	13,385
Accretion of discount (amortization of premium)	48	41
Purchases	4,681	1,196
Paid-in-kind interest	108	115
Sales and repayments	(5,264)	(1,950)
Transfers into Level 3	8	330
Transfers out of Level 3	0	0
Fair value at end of period	12,467	13,031
The amount of total gains or losses for the period included in changes in net assets attributable to the change in unrealized gains or losses relating to investments still held at the reporting date	(159)	(86)
Investments | Net Senior Secured Loans—First Lien
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at beginning of period	8,429	9,124
Accretion of discount (amortization of premium)	35	34
Purchases	3,770	1,040
Paid-in-kind interest	67	43
Sales and repayments	(3,864)	(1,583)
Transfers into Level 3	8	33
Transfers out of Level 3	0	0
Fair value at end of period	8,341	8,646
The amount of total gains or losses for the period included in changes in net assets attributable to the change in unrealized gains or losses relating to investments still held at the reporting date	(53)	(49)
Investments | Net Senior Secured Loans—Second Lien
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at beginning of period	1,090	874
Accretion of discount (amortization of premium)	6	4
Purchases	56	16
Paid-in-kind interest	2	24
Sales and repayments	(268)	(115)
Transfers into Level 3	0	297
Transfers out of Level 3	0	0
Fair value at end of period	866	1,096
The amount of total gains or losses for the period included in changes in net assets attributable to the change in unrealized gains or losses relating to investments still held at the reporting date	(10)	(35)
Investments | Other Senior Secured Debt
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at beginning of period	21	22
Accretion of discount (amortization of premium)	0	0
Purchases	25	0
Paid-in-kind interest	1	1
Sales and repayments	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Fair value at end of period	45	21
The amount of total gains or losses for the period included in changes in net assets attributable to the change in unrealized gains or losses relating to investments still held at the reporting date	(2)	37
Investments | Net Subordinated Debt
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at beginning of period	322	264
Accretion of discount (amortization of premium)	2	0
Purchases	29	8
Paid-in-kind interest	20	19
Sales and repayments	(143)	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Fair value at end of period	221	297
The amount of total gains or losses for the period included in changes in net assets attributable to the change in unrealized gains or losses relating to investments still held at the reporting date	(9)	5
Investments | Net Asset Based Finance
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at beginning of period	2,077	1,902
Accretion of discount (amortization of premium)	2	2
Purchases	632	93
Paid-in-kind interest	6	6
Sales and repayments	(760)	(207)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Fair value at end of period	1,990	1,739
The amount of total gains or losses for the period included in changes in net assets attributable to the change in unrealized gains or losses relating to investments still held at the reporting date	(2)	(67)
Investments | Equity/Other
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at beginning of period	1,134	1,199
Accretion of discount (amortization of premium)	3	1
Purchases	169	39
Paid-in-kind interest	12	22
Sales and repayments	(229)	(45)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Fair value at end of period	1,004	1,232
The amount of total gains or losses for the period included in changes in net assets attributable to the change in unrealized gains or losses relating to investments still held at the reporting date	(83)	23
Investments | Net realized gain (loss)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	(335)	(328)
Investments | Net realized gain (loss) | Net Senior Secured Loans—First Lien
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	(170)	(15)
Investments | Net realized gain (loss) | Net Senior Secured Loans—Second Lien
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	(112)	(55)
Investments | Net realized gain (loss) | Other Senior Secured Debt
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	(3)	(39)
Investments | Net realized gain (loss) | Net Subordinated Debt
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	0	(126)
Investments | Net realized gain (loss) | Net Asset Based Finance
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	(36)	8
Investments | Net realized gain (loss) | Equity/Other
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	(14)	(101)
Investments | Net change in unrealized appreciation (depreciation)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	148	242
Investments | Net change in unrealized appreciation (depreciation) | Net Senior Secured Loans—First Lien
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	66	(30)
Investments | Net change in unrealized appreciation (depreciation) | Net Senior Secured Loans—Second Lien
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	92	51
Investments | Net change in unrealized appreciation (depreciation) | Other Senior Secured Debt
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	1	37
Investments | Net change in unrealized appreciation (depreciation) | Net Subordinated Debt
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	(9)	132
Investments | Net change in unrealized appreciation (depreciation) | Net Asset Based Finance
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	69	(65)
Investments | Net change in unrealized appreciation (depreciation) | Equity/Other
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	$ (71)	$ 117