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Significant Accounting Policies - Revenues From Contracts with Customers (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation of Revenue [Line Items]
Revenue earned	$ 35,927,715	$ 35,542,541	$ 73,709,717	$ 70,581,614
Investment advisory
Disaggregation of Revenue [Line Items]
Revenue earned	33,526,273	32,558,324	68,157,563	64,323,301
Mutual fund administration, net
Disaggregation of Revenue [Line Items]
Revenue earned	2,401,442	2,984,217	5,552,154	6,258,313
Proprietary funds
Disaggregation of Revenue [Line Items]
Revenue earned	28,696,350	28,537,994	59,152,260	56,662,161
Proprietary funds | Investment advisory
Disaggregation of Revenue [Line Items]
Revenue earned	26,294,908	25,553,777	53,600,106	50,403,848
Proprietary funds | Mutual fund administration, net
Disaggregation of Revenue [Line Items]
Revenue earned	2,401,442	2,984,217	5,552,154	6,258,313
Sub-advised funds and institutional accounts
Disaggregation of Revenue [Line Items]
Revenue earned	7,231,365	7,004,547	14,557,457	13,919,453
Sub-advised funds and institutional accounts | Investment advisory
Disaggregation of Revenue [Line Items]
Revenue earned	7,231,365	7,004,547	14,557,457	13,919,453
Sub-advised funds and institutional accounts | Mutual fund administration, net
Disaggregation of Revenue [Line Items]
Revenue earned	$ 0	$ 0	$ 0	$ 0

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+ References

No definition available.

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Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 32
-Paragraph 2A
-URI http://asc.fasb.org/extlink&oid=82859839&loc=SL82860478-203043

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130543-203045

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130539-203045

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130545-203045

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