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Significant Accounting Policies - Narrative (Detail) | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2015 USD ($) | Jun. 30, 2014 USD ($) | Jun. 30, 2015 USD ($) Segment | Jun. 30, 2014 USD ($) | Dec. 31, 2014 USD ($)
Business Organization And Significant Accounting Policies [Line Items] |  |  |  |  |
Number of business segment | Segment |  |  | 1 |  |
Allowance for doubtful accounts | $ 0 |  | $ 0 |  | $ 0
Transfers between fair value levels | 0 |  | $ 0 |  | 0
Client Performance Period |  |  | 5 years |  |
Advance commissions amortization period |  |  | 12 months |  |
Contractual Expense Reimburse, Net | 666,749 | $ 401,313 | $ 1,214,504 | $ 797,354 |
Liability for Uncertain Tax Positions, Current | $ 0 |  | $ 0 |  | $ 0
Class A, C, and I Shares |  |  |  |  |
Business Organization And Significant Accounting Policies [Line Items] |  |  |  |  |
Rate of Administrative Service Fees | 0.24% |  | 0.24% |  | 0.25%
Class Y |  |  |  |  |
Business Organization And Significant Accounting Policies [Line Items] |  |  |  |  |
Rate of Administrative Service Fees | 0.10% |  | 0.10% |  | 0.10%
Mutual Funds | Money Market Funds | Level 1 Inputs |  |  |  |  |
Business Organization And Significant Accounting Policies [Line Items] |  |  |  |  |
Cash Equivalent Fair Value | $ 38,600,000 |  | $ 38,600,000 |  | $ 31,800,000
Incentive Fees Method One [Member] |  |  |  |  |
Business Organization And Significant Accounting Policies [Line Items] |  |  |  |  |
Performance Incentive Fees |  |  | $ 0 | $ 0 |

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