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Investment Securities - Investments, Debt and Equity Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Seed Investments
Marketable Securities [Line Items]
Seed investments in equity securities	$ 70,078	$ 66,349
Seed investments in equity securities accounted for under the equity method	2,119	7,964
Long-Term Cash Awards
Marketable Securities [Line Items]
Seed investments in equity securities	167,055	127,430
Seed investments in equity securities accounted for under the equity method	18,157	7,049
Consolidated Entity, Excluding VIE
Marketable Securities [Line Items]
Total investment securities	$ 257,409	$ 208,792

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