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Significant Accounting Policies - Mutual Fund Administration Gross and Net Revenue (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue from External Customer [Line Items]
Revenue	$ 55,054,554	$ 31,175,755	$ 139,138,640	$ 91,350,429
Administration revenue, gross
Revenue from External Customer [Line Items]
Revenue	7,436,287	5,571,022	22,466,306	16,144,295
Fund related expense
Revenue from External Customer [Line Items]
Expenses	4,230,112	3,766,667	13,446,649	11,028,882
Revenue, net of related expenses
Revenue from External Customer [Line Items]
Revenue	3,206,175	1,804,355	9,019,657	5,115,413
Broker Commission
Revenue from External Customer [Line Items]
Revenue	0	60,634	33,595	190,993
Expenses	0	51,886	48,521	175,302
Financing activity, net
Revenue from External Customer [Line Items]
Revenue	0	8,748	(14,926)	15,691
Mutual fund administration revenue, net
Revenue from External Customer [Line Items]
Revenue	$ 3,206,175	$ 1,813,103	$ 9,004,731	$ 5,131,104

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