Segment Reporting - Consolidated Revenues and Assets Based on Geographical Focus of Associated Investment Vehicle (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Share of total revenues	$ 2,963.9	$ 4,438.7	$ 8,782.1
Percentages of revenue by geographic regions	100.00%	100.00%	100.00%
Consolidated VIEs, assets	$ 21,176.0	$ 21,403.0	$ 21,250.4
Percentage of assets by geographic regions	100.00%	100.00%	100.00%
Americas
Segment Reporting Information [Line Items]
Share of total revenues	$ 1,289.0	$ 2,560.0	$ 5,434.6
Percentages of revenue by geographic regions	44.00%	58.00%	62.00%
Consolidated VIEs, assets	$ 11,129.2	$ 11,662.8	$ 10,874.2
Percentage of assets by geographic regions	52.00%	55.00%	51.00%
EMEA
Segment Reporting Information [Line Items]
Share of total revenues	$ 1,318.9	$ 1,603.8	$ 2,629.3
Percentages of revenue by geographic regions	44.00%	36.00%	30.00%
Consolidated VIEs, assets	$ 8,797.2	$ 8,632.9	$ 8,920.4
Percentage of assets by geographic regions	42.00%	40.00%	42.00%
Asia-Pacific
Segment Reporting Information [Line Items]
Share of total revenues	$ 356.0	$ 274.9	$ 718.2
Percentages of revenue by geographic regions	12.00%	6.00%	8.00%
Consolidated VIEs, assets	$ 1,249.6	$ 1,107.3	$ 1,455.8
Percentage of assets by geographic regions	6.00%	5.00%	7.00%