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Significant Accounting Policies - Narrative (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) Segment	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Business Organization And Significant Accounting Policies [Line Items]
Number of business segment | Segment			1
Accounts receivable, related parties	$ 8,900,000		$ 8,900,000		$ 10,700,000
Client performance period			5 years
Revenue	31,175,755	$ 34,592,372	$ 91,350,429	$ 100,716,763
Advance commissions amortization period			12 months
Variable Rate Fees
Business Organization And Significant Accounting Policies [Line Items]
Revenue	$ 700,000	$ 500,000	$ 1,900,000	$ 1,300,000

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