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Investments - Summary of Market Value of Investments (Detail) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Investment Holdings [Line Items]
Company sponsored equity method investments	$ 61,143,224	$ 16,339,649
Total Investments	133,978,699	203,488,217
Securities held in Consolidated Funds
Investment Holdings [Line Items]
Fair value investments	29,635,079	153,730,480
Securities held in Consolidated Funds | Parent
Investment Holdings [Line Items]
Fair value investments	18,800,000	84,700,000
Securities held in Consolidated Funds | Redeemable Noncontrolling Interest
Investment Holdings [Line Items]
Fair value investments	10,800,000	69,000,000.0
Company sponsored investments
Investment Holdings [Line Items]
Fair value investments	$ 43,200,396	$ 33,418,088

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