Fair Value of Financial Instruments - Roll Forward Level III (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Accretion of discount (amortization of premium)	$ 29	$ 50
Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at beginning of period	13,385	13,972
Accretion of discount (amortization of premium)	27	47
Purchases	652	3,021
Paid-in-kind interest	58	58
Sales and repayments	(1,256)	(2,893)
Transfers into Level 3	33	0
Transfers out of Level 3	0	0
Fair value at end of period	12,839	14,004
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	(78)	(390)
Investments | Senior Secured Loans—First Lien
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at beginning of period	9,124	9,542
Accretion of discount (amortization of premium)	23	37
Purchases	562	1,920
Paid-in-kind interest	28	20
Sales and repayments	(1,072)	(1,549)
Transfers into Level 3	33	0
Transfers out of Level 3	0	0
Fair value at end of period	8,665	9,797
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	(41)	(175)
Investments | Senior Secured Loans—Second Lien
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at beginning of period	874	1,205
Accretion of discount (amortization of premium)	2	5
Purchases	3	8
Paid-in-kind interest	0	1
Sales and repayments	(5)	(186)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Fair value at end of period	853	971
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	(22)	(66)
Investments | Other Senior Secured Debt
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at beginning of period	22	29
Accretion of discount (amortization of premium)	0	0
Purchases	0	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	21	22
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)	(8)
Investments | Subordinated Debt
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at beginning of period	264	74
Accretion of discount (amortization of premium)	1	0
Purchases	8	42
Paid-in-kind interest	10	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	287	78
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	4	(39)
Investments | Asset Based Finance
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at beginning of period	1,902	2,245
Accretion of discount (amortization of premium)	1	4
Purchases	67	711
Paid-in-kind interest	4	18
Sales and repayments	(163)	(798)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Fair value at end of period	1,779	2,113
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	(39)	(107)
Investments | Equity/Other
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at beginning of period	1,199	877
Accretion of discount (amortization of premium)	0	1
Purchases	12	340
Paid-in-kind interest	15	17
Sales and repayments	(16)	(360)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Fair value at end of period	1,234	1,023
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	22	5
Investments | Net realized gain (loss)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	(262)	154
Investments | Net realized gain (loss) | Senior Secured Loans—First Lien
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	1	(62)
Investments | Net realized gain (loss) | Senior Secured Loans—Second Lien
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	(48)	(42)
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)	0	0
Investments | Net realized gain (loss) | Subordinated Debt
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	(126)	0
Investments | Net realized gain (loss) | Asset Based Finance
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	7	51
Investments | Net realized gain (loss) | Equity/Other
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	(96)	207
Investments | Net change in unrealized appreciation (depreciation)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	202	(355)
Investments | Net change in unrealized appreciation (depreciation) | Senior Secured Loans—First Lien
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	(34)	(111)
Investments | Net change in unrealized appreciation (depreciation) | Senior Secured Loans—Second Lien
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	27	(20)
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)	(2)	(8)
Investments | Net change in unrealized appreciation (depreciation) | Subordinated Debt
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	130	(39)
Investments | Net change in unrealized appreciation (depreciation) | Asset Based Finance
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Net realized gain (loss)	(39)	(118)
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)	$ 120	$ (59)