Financial Instruments and Fair Value Measurement	9 Months Ended
Financial Instruments and Fair Value Measurement	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Financial Instruments and Fair Value Measurement	5. Financial Instruments and Fair Value Measurement Financial instruments are measured at fair value. The fair value of a financial instrument is defined as the price that would be received to sell an asset or paid to transfer a liability (i.e., “the exit price”) in an orderly transaction between market participants at the measurement date. Accounting Standards Codification (“ASC”) Topic 820, Fair Value Measurements establishes a hierarchy for inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the most observable inputs be used when available. Observable inputs are inputs that market participants would use in pricing the asset or liability developed based on market data obtained from independent sources. Unobservable inputs reflect assumptions that market participants would use in pricing the asset or liability developed based on the best information available in the circumstances. The hierarchy is broken down into three levels based on the transparency of inputs as follows: Level 1 – Quoted prices for identical instruments in active markets. Level 2 – Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations whose inputs are observable or whose significant value drivers are observable. Level 3 – Instruments whose significant drivers are unobservable. The availability of observable inputs can vary from product to product and is effected by a wide variety of factors, including, for example, the type of product, whether the product is new and not yet established in the marketplace, and other characteristics particular to the transaction. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by management in determining fair value is greatest for instruments categorized in Level 3. In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, for disclosure purposes, the level in the fair value hierarchy within which the fair value measurement in its entirety falls is determined based on the lowest level input that is significant to the fair value measurement in its entirety. Fair Valuation Methodology Cash and Cash Equivalents – These financial assets represent cash in banks or cash invested in highly liquid investments with original maturities less than 90 days. These investments are valued at par, which represent fair value, and are considered Level 1 (See Note 3). Investments (Held-to-Maturity) – These financial instruments are Federal agency debt instruments which are instruments that are generally traded in active, quoted and highly liquid markets and are therefore classified as Level 1 within the fair value hierarchy (See Note 4). Financial Instruments Owned/Sold But Not Yet Purchased (Trading Securities) – These financial instruments consist of exchange traded funds which are instruments that are generally traded in active, quoted and highly liquid markets and are therefore classified as Level 1 within the fair value hierarchy. The Company’s financial instruments owned and financial instruments sold, but not yet purchased were $125 and $114, respectively at September 30, 2016 and are reported within Other assets and Other liabilities on its Consolidated Balance Sheets. There were no financial instruments owned and financial instruments sold, but not yet purchased at December 31, 2015. Acquisition Payable (See Note 13) – As of December 31, 2015, the Company estimated the fair value of the acquisition payable related to the acquisition of U.K. based ETP sponsor, Boost, to be $9,900. The fair value measurement of the acquisition payable was categorized as Level 3 and was based on a predefined formula that included the following inputs: the contractual minimum payment obligation, European AUM, the Company’s enterprise value over global AUM, and operating results of the European business. In May 2016, the Company accelerated the buyout of the remaining minority interest in Boost. At each reporting period through May 2016, the fair value of the acquisition payable was determined using a discounted cash flows analysis. The significant unobservable inputs used in the fair value measurement were the projected AUM of the European listed ETPs (ranging from $1,000,000 to $6,000,000), the projected operating results of the European business, and the discount rate (27.5%). Significant increases (decreases) to the projected AUM of the European listed ETPs or operating results of the European business in isolation would have resulted in a higher (lower) fair value measurement. Significant increases (decreases) to the discount rate in isolation would have resulted in a lower (higher) fair value measurement.

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.