Segment Reporting - Revenue Adjustments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting Information [Line Items]
Total revenues	$ 1,069.7	$ 462.1	$ 1,758.1	$ 1,321.1
Reconciling Items
Segment Reporting Information [Line Items]
Unrealized performance and fee related performance revenues	47.4	(600.5)	(474.2)	(621.2)
Unrealized principal investment income (loss)	48.1	30.4	52.5	1.4
Adjustments related to expenses associated with investments in NGP Management and its affiliates	(3.8)	(4.1)	(7.0)	(7.5)
Non-controlling interests and other adjustments to present certain costs on a net basis	36.2	43.9	77.7	94.7
Total revenues	115.2	(652.9)	(384.3)	(670.0)
Reconciling Items | Fortitude Group Holdings, LLC
Segment Reporting Information [Line Items]
Principal investment loss from dilution of indirect investment in Fortitude	0.0	(104.0)	0.0	(104.0)
Elimination of revenues of Consolidated Funds
Segment Reporting Information [Line Items]
Total revenues	$ (12.7)	$ (18.6)	$ (33.3)	$ (33.4)