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Investment Portfolio - Narrative (Detail) - USD ($) | 9 Months Ended |
--- | --- | ---
Sep. 30, 2018 | Dec. 31, 2017
Total Investment portfolio | $ 212,389,477 | $ 138,476,022
New consolidations of Company sponsored investments | 16,444,640 |
Securities held in Consolidated Funds |  |
Fair value investments | 153,499,790 | 65,890,500
Parent | Securities held in Consolidated Funds |  |
Fair value investments | 85,900,000 | 42,600,000
Redeemable Noncontrolling Interest | Securities held in Consolidated Funds |  |
Fair value investments | $ 67,600,000 | $ 23,300,000

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