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Significant Accounting Policies - Narrative (Detail) | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2019 USD ($) | Sep. 30, 2018 USD ($) | Sep. 30, 2019 USD ($) Segment | Sep. 30, 2018 USD ($) | Dec. 31, 2018 USD ($)
Business Organization And Significant Accounting Policies [Line Items] |  |  |  |  |
Number of business segment | Segment |  |  | 1 |  |
Accounts receivable, related parties | $ 9,900,000 |  | $ 9,900,000 |  | $ 9,400,000
Client performance period |  |  | 5 years |  |
Revenue | 34,592,372 | $ 37,471,647 | $ 100,716,763 | $ 111,181,363 |
Advance commissions amortization period |  |  | 12 months |  |
Variable Rate Fees |  |  |  |  |
Business Organization And Significant Accounting Policies [Line Items] |  |  |  |  |
Revenue | $ 900,000 | $ 600,000 | $ 900,000 | $ 600,000 |

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