DEBT - Outstanding Debt (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Total Aggregate Principal Amount Committed/Outstanding	$ 18,029	$ 16,851
Principal Amount Outstanding	13,487	11,905
Carrying Value	13,500	11,884
Revolving Credit Facility
Debt Instrument [Line Items]
Borrowing capacity increase under line of credit	6,732	7,137
SMBC Funding Facility
Debt Instrument [Line Items]
Borrowing capacity increase under line of credit	1,000
2024-1 CLO Notes
Debt Instrument [Line Items]
Principal Amount Outstanding	702
Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Total Aggregate Principal Amount Committed/Outstanding	4,513	4,758
Principal Amount Outstanding	1,713	1,413
Carrying Value	1,713	1,413
Line of Credit | Revolving Funding Facility
Debt Instrument [Line Items]
Total Aggregate Principal Amount Committed/Outstanding	1,775	1,775
Principal Amount Outstanding	822	863
Carrying Value	822	863
Line of Credit | SMBC Funding Facility
Debt Instrument [Line Items]
Total Aggregate Principal Amount Committed/Outstanding	800	800
Principal Amount Outstanding	492	401
Carrying Value	492	401
Line of Credit | BNP Funding Facility
Debt Instrument [Line Items]
Total Aggregate Principal Amount Committed/Outstanding	1,265	865
Principal Amount Outstanding	784	575
Carrying Value	784	575
Secured Debt | 2024-1 CLO Notes
Debt Instrument [Line Items]
Total Aggregate Principal Amount Committed/Outstanding	476	0
Principal Amount Outstanding	476	0
Carrying Value	473	0
Convertible Debt | 2024-1 CLO Notes
Debt Instrument [Line Items]
Principal Amount Outstanding	476	0
Convertible Debt | 2024 Convertible Notes
Debt Instrument [Line Items]
Total Aggregate Principal Amount Committed/Outstanding	0	403
Principal Amount Outstanding	0	403
Carrying Value	0	402
Senior Notes | June 2024 Notes
Debt Instrument [Line Items]
Total Aggregate Principal Amount Committed/Outstanding	0	900
Principal Amount Outstanding	0	900
Carrying Value	0	899
Senior Notes | March 2025 Notes
Debt Instrument [Line Items]
Total Aggregate Principal Amount Committed/Outstanding	600	600
Principal Amount Outstanding	600	600
Carrying Value	600	599
Senior Notes | July 2025 Notes
Debt Instrument [Line Items]
Total Aggregate Principal Amount Committed/Outstanding	1,250	1,250
Principal Amount Outstanding	1,250	1,250
Carrying Value	1,252	1,255
Senior Notes | January 2026 Notes
Debt Instrument [Line Items]
Total Aggregate Principal Amount Committed/Outstanding	1,150	1,150
Principal Amount Outstanding	1,150	1,150
Carrying Value	1,148	1,146
Senior Notes | July 2026 Notes
Debt Instrument [Line Items]
Total Aggregate Principal Amount Committed/Outstanding	1,000	1,000
Principal Amount Outstanding	1,000	1,000
Carrying Value	995	993
Senior Notes | January 2027 Notes
Debt Instrument [Line Items]
Total Aggregate Principal Amount Committed/Outstanding	900	900
Principal Amount Outstanding	900	900
Carrying Value	909	905
Senior Notes | June 2027 Notes
Debt Instrument [Line Items]
Total Aggregate Principal Amount Committed/Outstanding	500	500
Principal Amount Outstanding	500	500
Carrying Value	496	495
Senior Notes | June 2028 Notes
Debt Instrument [Line Items]
Total Aggregate Principal Amount Committed/Outstanding	1,250	1,250
Principal Amount Outstanding	1,250	1,250
Carrying Value	1,248	1,247
Senior Notes | March 2029 Notes
Debt Instrument [Line Items]
Total Aggregate Principal Amount Committed/Outstanding	1,000	0
Principal Amount Outstanding	1,000	0
Carrying Value	1,005	0
Senior Notes | July 2029 Notes
Debt Instrument [Line Items]
Total Aggregate Principal Amount Committed/Outstanding	850	0
Principal Amount Outstanding	850	0
Carrying Value	871	0
Senior Notes | November 2031 Notes
Debt Instrument [Line Items]
Total Aggregate Principal Amount Committed/Outstanding	700	700
Principal Amount Outstanding	700	700
Carrying Value	$ 692	$ 691