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Significant Accounting Policies - Mutual Fund Administration Gross and Net Revenue (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenue from External Customer [Line Items]
Revenue	$ 45,069,653	$ 28,248,929	$ 84,084,086	$ 60,174,674
Administration revenue, gross
Revenue from External Customer [Line Items]
Revenue	8,103,606	4,980,615	15,030,019	10,573,273
Fund related expense
Revenue from External Customer [Line Items]
Expenses	4,750,380	3,434,966	9,216,537	7,262,215
Revenue, net of related expenses
Revenue from External Customer [Line Items]
Revenue	3,353,226	1,545,649	5,813,482	3,311,058
Broker Commission
Revenue from External Customer [Line Items]
Revenue	0	66,817	33,594	130,359
Expenses	0	62,530	48,520	123,416
Financing activity, net
Revenue from External Customer [Line Items]
Revenue	0	4,287	(14,926)	6,943
Mutual fund administration revenue, net
Revenue from External Customer [Line Items]
Revenue	$ 3,353,226	$ 1,549,936	$ 5,798,556	$ 3,318,001

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