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Significant Accounting Policies - Assets under Management (AUM) Subject to Incentive Fees and Incentive Fees (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Principal Transaction Revenue [Line Items]
AUM Subject to Incentive Fees	$ 524,380,560	$ 535,817,741
Incentive Fees Under Method 2
Principal Transaction Revenue [Line Items]
Performance Incentive Fees	1,862,436	2,574,724
Incentive Fees Under Method 2 | Quarter Ended June 30, 2017
Principal Transaction Revenue [Line Items]
Performance Incentive Fees	1,195,007	2,571,390
Incentive Fees Under Method 2 | Quarter Ended December 31, 2018
Principal Transaction Revenue [Line Items]
Performance Incentive Fees	325,730	0
Incentive Fees Under Method 2 | Quarter Ended September 30, 2019
Principal Transaction Revenue [Line Items]
Performance Incentive Fees	341,699	3,334
Incentive Fees Under Method 2 | Quarter Ended March 31, 2020
Principal Transaction Revenue [Line Items]
Performance Incentive Fees	$ 0	$ 0

X

- Definition

Assets under management (AUM) subject to incentive fees and incentive fees.

+ References

No definition available.

+ Details

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X

- Definition

Amount of revenue earned by the entity based on the investment results achieved. Excludes fees based upon a percentage of the assets under management not performance-related.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef



-Publisher FASB



-Name Accounting Standards Codification



-Topic 942



-SubTopic 225



-Section S99



-Paragraph 1



-Subparagraph (SX 210.9-04.13 (a))



-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

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- Definition

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+ References

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