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Significant Accounting Policies - Revenues From Contracts with Customers (Details) - USD ($) | 3 Months Ended
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Mar. 31, 2019 | Mar. 31, 2018
Disaggregation of Revenue [Line Items] |  |
Revenue | $ 32,579,373 | $ 37,782,002
Investment advisory |  |
Disaggregation of Revenue [Line Items] |  |
Revenue | 30,512,718 | 34,631,290
Mutual fund administration, net |  |
Disaggregation of Revenue [Line Items] |  |
Revenue | 2,066,655 | 3,150,712
Proprietary funds |  |
Disaggregation of Revenue [Line Items] |  |
Revenue | 25,646,532 | 30,455,911
Proprietary funds | Investment advisory |  |
Disaggregation of Revenue [Line Items] |  |
Revenue | 23,579,877 | 27,305,199
Proprietary funds | Mutual fund administration, net |  |
Disaggregation of Revenue [Line Items] |  |
Revenue | 2,066,655 | 3,150,712
Sub-advised funds and institutional accounts |  |
Disaggregation of Revenue [Line Items] |  |
Revenue | 6,932,841 | 7,326,091
Sub-advised funds and institutional accounts | Investment advisory |  |
Disaggregation of Revenue [Line Items] |  |
Revenue | 6,932,841 | 7,326,091
Sub-advised funds and institutional accounts | Mutual fund administration, net |  |
Disaggregation of Revenue [Line Items] |  |
Revenue | $ 0 | $ 0

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- Definition 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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130543-203045 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130539-203045 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130545-203045 + Details
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