FAIR VALUE OF FINANCIAL INSTRUMENTS - Significant Unobservable Inputs (Details) $ in Millions	Dec. 31, 2024 USD ($)		Dec. 31, 2023 USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	$ 26,719.9	[1]	$ 22,873.7	[2]
Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	26,091.0		22,084.0
Level 3 | Yield analysis | First lien senior secured loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	14,722.0		9,584.0
Level 3 | Yield analysis | Second lien senior secured loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	1,724.0		3,536.0
Level 3 | Yield analysis | Senior subordinated loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	1,343.0		1,073.0
Level 3 | Yield analysis | Preferred equity
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	2,649.0		2,456.0
Level 3 | Discounted cash flow analysis | Subordinated certificates of the SDLP
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	1,192.0		1,288.0
Level 3 | Discounted cash flow analysis | Ivy Hill Asset Management, L.P.
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	1,915.0		1,987.0
Level 3 | EV market multiple analysis | Other equity
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	$ 2,546.0		$ 2,160.0
Level 3 | Market yield | Yield analysis | Minimum | First lien senior secured loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	0.038		0.064
Level 3 | Market yield | Yield analysis | Minimum | Second lien senior secured loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	0.096		0.100
Level 3 | Market yield | Yield analysis | Minimum | Senior subordinated loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	0.084		0.080
Level 3 | Market yield | Yield analysis | Minimum | Preferred equity
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	0.070		0.070
Level 3 | Market yield | Yield analysis | Maximum | First lien senior secured loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	0.229		0.350
Level 3 | Market yield | Yield analysis | Maximum | Second lien senior secured loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	0.232		0.373
Level 3 | Market yield | Yield analysis | Maximum | Senior subordinated loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	0.219		0.192
Level 3 | Market yield | Yield analysis | Maximum | Preferred equity
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	0.190		0.200
Level 3 | Market yield | Yield analysis | Weighted Average | First lien senior secured loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	0.104		0.127
Level 3 | Market yield | Yield analysis | Weighted Average | Second lien senior secured loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	0.142		0.148
Level 3 | Market yield | Yield analysis | Weighted Average | Senior subordinated loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	0.128		0.146
Level 3 | Market yield | Yield analysis | Weighted Average | Preferred equity
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	0.133		0.145
Level 3 | Discount rate | Discounted cash flow analysis | Minimum | Subordinated certificates of the SDLP
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	0.100		0.123
Level 3 | Discount rate | Discounted cash flow analysis | Minimum | Ivy Hill Asset Management, L.P.
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	0.099		0.116
Level 3 | Discount rate | Discounted cash flow analysis | Maximum | Subordinated certificates of the SDLP
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	0.130		0.146
Level 3 | Discount rate | Discounted cash flow analysis | Maximum | Ivy Hill Asset Management, L.P.
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	0.190		0.326
Level 3 | Discount rate | Discounted cash flow analysis | Weighted Average | Subordinated certificates of the SDLP
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	0.120		0.133
Level 3 | Discount rate | Discounted cash flow analysis | Weighted Average | Ivy Hill Asset Management, L.P.
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	0.114		0.142
Level 3 | EBITDA multiple | EV market multiple analysis | Minimum | Preferred equity
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	2.6		4.3
Level 3 | EBITDA multiple | EV market multiple analysis | Minimum | Other equity
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	5.6		5.3
Level 3 | EBITDA multiple | EV market multiple analysis | Maximum | Preferred equity
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	25.1		32.5
Level 3 | EBITDA multiple | EV market multiple analysis | Maximum | Other equity
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	49.7		33.8
Level 3 | EBITDA multiple | EV market multiple analysis | Weighted Average | Preferred equity
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	15.4		15.2
Level 3 | EBITDA multiple | EV market multiple analysis | Weighted Average | Other equity
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input	18.1		14.8

[1] As of December 31, 2024, the estimated net unrealized gain for federal tax purposes was $0.2 billion based on a tax cost basis of $26.5 billion. As of December 31, 2024, the estimated aggregate gross unrealized gain for federal income tax purposes was $1.7 billion and the estimated aggregate gross unrealized loss for federal income tax purposes was $1.5 billion.     

[2] As of December 31, 2023, the estimated net unrealized loss for federal tax purposes was $0.4 billion based on a tax cost basis of $22.5 billion. As of December 31, 2023, the estimated aggregate gross unrealized loss for federal income tax purposes was $1.7 billion and the estimated aggregate gross unrealized gain for federal income tax purposes was $1.3 billion.