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Investment Securities - Unrealized Gain (Loss) on Investments (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
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Jun. 30, 2023 | Jun. 30, 2022 | Jun. 30, 2023 | Jun. 30, 2022
Investments, Debt and Equity Securities [Abstract] |  |  |  |
Unrealized gain (loss) on investment securities held at the end of the period | $ 3,299 | $ (13,542) | $ 10,359 | $ (17,470)
Consolidated Entity Excluding Variable Interest Entities (VIE) |  |  |  |
Marketable Securities [Line Items] |  |  |  |
Other net investment gain (loss) | 4,224 | (13,414) | 13,481 | (18,166)
Seed Investments |  |  |  |
Marketable Securities [Line Items] |  |  |  |
Other net investment gain (loss) | (500) | (1,298) | 1,210 | (2,936)
Long-Term Cash Awards |  |  |  |
Marketable Securities [Line Items] |  |  |  |
Other net investment gain (loss) |  | (12,244) |  | (15,205)
Other |  |  |  |
Marketable Securities [Line Items] |  |  |  |
Other net investment gain (loss) | $ 1,161 | $ 128 | $ 1,690 | $ (25)

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