CONSOLIDATED INVESTMENT PRODUCTS - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Variable Interest Entity [Line Items]
Borrowings with fair value election	$ 7,121.8	$ 6,590.4
Carrying value and maximum risk of loss with respect to VIEs, unfunded	142.5	100.5
Significant Unobservable Inputs (Level 3)
Variable Interest Entity [Line Items]
Borrowings with fair value election	353.7
Deconsolidated VIEs
Variable Interest Entity [Line Items]
Carrying value and maximum risk of loss with respect to VIEs	$ 122.9	$ 111.5