Segment Reporting - Revenue Adjustments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Revenues	$ 2,963.9	$ 4,438.7	$ 8,782.1
Reconciling Items
Segment Reporting Information [Line Items]
Unrealized performance and fee related performance revenues	(1,046.6)	(142.5)	3,155.6
Unrealized principal investment income	36.1	(38.3)	351.8
Adjustments related to expenses associated with investments in NGP Management and its affiliates	(13.8)	(12.9)	(13.7)
Tax expense associated with certain foreign performance revenues	0.0	0.1	0.2
Non-controlling interests and other adjustments to present certain costs on a net basis	191.6	119.0	159.6
Revenues	(1,011.3)	(273.7)	3,578.8
Consolidation, Eliminations
Segment Reporting Information [Line Items]
Revenues	(74.6)	(22.2)	(74.7)
Fortitude Re | Reconciling Items
Segment Reporting Information [Line Items]
Principal investment loss from dilution of indirect investment in Fortitude	$ (104.0)	$ (176.9)	$ 0.0