Investments - Schedule of Investment Components (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Investment Holdings [Line Items]
Total investments per Condensed Consolidated Balance Sheets	$ 141.9	$ 141.6
Consolidated Funds
Investment Holdings [Line Items]
Investments	91.1	90.4
Total investments per Condensed Consolidated Balance Sheets	91.1	90.4
Consolidated Entity Excluding Consolidated Funds
Investment Holdings [Line Items]
Investments	13.4	13.3
Total investments per Condensed Consolidated Balance Sheets	50.8	51.2
Consolidated Entity Excluding Consolidated Funds | Other investments
Investment Holdings [Line Items]
Investments	13.4	13.3
Consolidated Entity Excluding Consolidated Funds | Investments related to long-term incentive compensation plans
Investment Holdings [Line Items]
Investments	$ 37.4	$ 37.9