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Significant Accounting Policies - Mutual Fund Administration Gross and Net Revenue (Detail) - USD ($) | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017
Mutual fund administration: |  |  |  |
Administration revenue, gross | $ 5,993,719 | $ 6,465,152 | $ 12,601,056 | $ 12,874,949
Fund related expense | 3,595,555 | 3,489,399 | 7,063,880 | 6,638,351
Revenue, net of related expenses | 2,398,164 | 2,975,753 | 5,537,176 | 6,236,598
Share Financing [Abstract] |  |  |  |
Broker commission advance repayments | 83,380 | 100,576 | 179,858 | 214,047
Broker commission amortization | (80,102) | (92,112) | (164,880) | (192,332)
Financing activity, net | 3,278 | 8,464 | 14,978 | 21,715
Mutual fund administration revenue, net | $ 2,401,442 | $ 2,984,217 | $ 5,552,154 | $ 6,258,313

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- Definition Broker commission advance repayments. + References No definition available. + Details
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- Definition Broker commission amortization. + References No definition available. + Details
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- Definition Financing activity, net. + References No definition available. + Details
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- Definition Mutual Fund Administration [Abstract] + References No definition available. + Details
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- Definition Revenue from administrative services excluding financial activity net. + References No definition available. + Details
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- Definition Revenue from administrative services net. + References No definition available. + Details
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- Definition Share Financing [Abstract] + References No definition available. + Details
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- Definition Amount of revenue from providing administrative services, including, but not limited to, accounting, tax, legal, regulatory filing, and share registration activities of managed funds and investment accounts of independent third parties and related and affiliated entities. + References No definition available. + Details
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