Investments (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Investment Holdings [Line Items]
Total investments per Condensed Consolidated Balance Sheets	$ 139.7	$ 98.6
Consolidated Funds
Investment Holdings [Line Items]
Investments	71.2	33.9
Total investments per Condensed Consolidated Balance Sheets	71.2	33.9
Consolidated Entity Excluding Consolidated Funds
Investment Holdings [Line Items]
Total investments per Condensed Consolidated Balance Sheets	68.5	64.7
Consolidated Entity Excluding Consolidated Funds | Other investments
Investment Holdings [Line Items]
Investments	19.7	20.0
Consolidated Entity Excluding Consolidated Funds | Investments related to long-term incentive compensation plans
Investment Holdings [Line Items]
Investments	$ 48.8	$ 44.7