Basis of Presentation and Significant Accounting Policies	3 Months Ended
Mar. 31, 2018
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	Basis of Presentation and Significant Accounting Policies Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") for interim financial information. Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. In the opinion of management, these financial statements contain all adjustments, consisting only of normal recurring adjustments, necessary for a fair statement of the Company’s financial condition and results of operations. Operating results for the three months ended March 31, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 filed with the Securities and Exchange Commission. The Company’s significant accounting policies, which have been consistently applied, are summarized in its 2017 Annual Report on Form 10-K. The Company has reclassified certain amounts in prior-period financial statements to conform to the current period's presentation. Previously, the Company reported consolidated investment products and consolidated sponsored investment products separately. Currently, the Company combines these categories under the caption "consolidated investment products" and has accordingly reclassified prior presentations. The reclassifications were not material to the condensed consolidated financial statements. New Accounting Standards Implemented Accounting Standards Update ("ASU") 2014-09, Revenue from Contracts with Customers. On January 1, 2018, the Company adopted the new Accounting Standards Codification ("ASC") 606, Revenue from Contracts with Customers ("ASC 606"), and all the related amendments ("the new revenue standard") using the modified retrospective approach. The core principle of the new revenue standard is that revenue is recognized upon the transfer of promised goods or services to customers in an amount that reflects the expected consideration to be received for the goods or services. Based on the revised criteria in the new revenue standard for determining whether the Company is acting as a principal or agent, certain costs that were previously presented on a net of revenue basis are now presented on a gross basis. The comparative periods have not been restated and continue to be reported under the accounting standards in effect for those periods. No cumulative-effect adjustment to the balance sheet was necessary upon the adoption of ASC 606. The Company has determined that the adoption of the new revenue standard did not have a material impact the Company's condensed consolidated financial statements. ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities ("ASU 2016-01"). On January 1, 2018, the Company adopted amendments to ASC 825 - Financial Instruments ("ASC 825) pursuant to ASU 2016-01. This standard requires all equity investments (other than those accounted for under the equity method) to be measured at fair value with changes in the fair value recognized through net income. The Company recorded a $0.2 million cumulative-effect adjustment to the balance sheet upon adoption. ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments ("ASU 2016-15"). On January 1, 2018, the Company adopted amendments to ASC 230 - Statement of Cash Flows ("ASC 230") on a retrospective basis pursuant to ASU 2016-15. This standard clarifies the treatment of several cash flow activities. ASU 2016-15 also clarifies that when cash receipts and cash payments have aspects of more than one classification of cash flows and cannot be separated, classification will depend on the predominant source or use. The adoption of this standard did not have a material impact on the Company's condensed consolidated financial statements. ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash ("ASU 2016-18"). On January 1, 2018, the Company adopted amendments to ASC 230 on a retrospective basis pursuant to ASU 2016-18. This standard requires the inclusion of restricted cash with cash and cash equivalents when reconciling the beginning and ending cash on the statement of cash flows. Restricted cash includes cash pledged or on deposit with brokers of consolidated investment products. Cash, cash equivalents and restricted cash reported on the condensed consolidated statements of cash flows now includes $0.8 million, $1.1 million and $1.0 million of cash pledged or on deposit of consolidated investment products as of December 31, 2017, March 31, 2017, and December 31, 2016, respectively, as well as previously reported cash and cash equivalents. The adoption of this standard did not have a material impact on the Company's condensed consolidated financial statements. ASU 2017-01, Clarifying the Definition of a Business ("ASU 2017-01"). On January 1, 2018, the Company adopted amendments to ASC 805 - Business Combinations ("ASC 805") and will apply the standard prospectively pursuant to ASU 2017-01. This standard provides guidance on evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The impact of ASU 2017-01 on the Company’s condensed consolidated financial statements will depend on acquisitions (or disposals) of assets or businesses by the Company in periods following adoption. ASU 2017-04, Intangibles - Goodwill and Other: Simplifying the Accounting for Goodwill Impairment ("ASU 2017-04"). On January 1, 2018, the Company adopted amendments to ASC 350 - Intangibles Goodwill and Other and will apply the standard prospectively for all future annual and interim goodwill impairment tests pursuant to ASU 2017-04. Under ASU 2017-04, a goodwill impairment is defined to be the amount by which a reporting unit’s carrying value exceeds its fair value. The impact of the new standard on the Company’s condensed consolidated financial statements will depend on the outcomes of future goodwill impairment tests. ASU 2018-05, Income Taxes (Topic 740), Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118 ("ASU 2018-05"). In March 2018, the Company adopted the amendments to ASC 740 - Income Taxes pursuant to ASU 2018-05. The standard adds various Securities and Exchange Commission ("SEC") paragraphs pursuant to the issuance of the December 2017 SEC Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act ("SAB 118"), which was effective immediately. The SEC issued SAB 118 to address concerns about reporting entities’ ability to timely comply with the accounting requirements to recognize all of the effects of the Tax Cuts and Jobs Act in the period of enactment. SAB 118 allows disclosure that timely determination of some or all of the income tax effects from the Tax Cuts and Jobs Act are incomplete by the due date of the financial statements and if possible to provide a reasonable estimate. We have accounted for the tax effects of the Tax Cuts and Jobs Act under the guidance of SAB 118, on a provisional basis. Our accounting for certain income tax effects is incomplete, but we have determined reasonable estimates for those effects and have recorded provisional amounts in our condensed consolidated financial statements as of March 31, 2018 and December 31, 2017. New Accounting Standards Not Yet Implemented In February 2018, the FASB issued ASU 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income ("ASU 2018-02"). The standard provides financial statement preparers with an option to reclassify stranded tax effects within accumulated other comprehensive income to retained earnings in each period in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Cuts and Jobs Act (or portion thereof) is recorded. ASU 2018-02 is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption is permitted. The Company does not expect the adoption of this guidance to have a material impact on the Company's condensed consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) ("ASU 2016-02"). The standard replaces current codification Topic 840 - Leases with updated guidance on accounting for leases and requires a lessee to recognize assets and liabilities arising from an operating lease on the balance sheet, whereas previous guidance did not require lease assets and liabilities to be recognized for most leases. Furthermore, this standard permits companies to make an accounting policy election to not recognize lease assets and liabilities for leases with a term of 12 months or less. For both finance leases and operating leases, the lease liability should be initially measured at the present value of the lease payments. The recognition, measurement and presentation of expenses and cash flows arising from a lease by a lessee will not significantly change under this new guidance. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018 and interim periods therein. Early adoption is permitted. The Company is currently evaluating the potential impact of this standard on its condensed consolidated financial statements but expects to record a right-of-use asset and a related lease obligation in the Company's condensed consolidated balance sheet upon adoption.

Basis of Presentation and Significant Accounting Policies

Basis of Presentation

The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") for interim financial information. Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. In the opinion of management, these financial statements contain all adjustments, consisting only of normal recurring adjustments, necessary for a fair statement of the Company’s financial condition and results of operations. Operating results for the three months ended March 31, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018.

These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 filed with the Securities and Exchange Commission. The Company’s significant accounting policies, which have been consistently applied, are summarized in its 2017 Annual Report on Form 10-K.

The Company has reclassified certain amounts in prior-period financial statements to conform to the current period's presentation. Previously, the Company reported consolidated investment products and consolidated sponsored investment products separately. Currently, the Company combines these categories under the caption "consolidated investment products" and has accordingly reclassified prior presentations. The reclassifications were not material to the condensed consolidated financial statements.

New Accounting Standards Implemented

Accounting Standards Update ("ASU") 2014-09, Revenue from Contracts with Customers. On January 1, 2018, the Company adopted the new Accounting Standards Codification ("ASC") 606, Revenue from Contracts with Customers ("ASC 606"), and all the related amendments ("the new revenue standard") using the modified retrospective approach. The core principle of the new revenue standard is that revenue is recognized upon the transfer of promised goods or services to customers in an amount that reflects the expected consideration to be received for the goods or services. Based on the revised criteria in the new revenue standard for determining whether the Company is acting as a principal or agent, certain costs that were previously presented on a net of revenue basis are now presented on a gross basis. The comparative periods have not been restated and continue to be reported under the accounting standards in effect for those periods. No cumulative-effect adjustment to the balance sheet was necessary upon the adoption of ASC 606. The Company has determined that the adoption of the new revenue standard did not have a material impact the Company's condensed consolidated financial statements.

ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities ("ASU 2016-01"). On January 1, 2018, the Company adopted amendments to ASC 825 - Financial Instruments ("ASC 825) pursuant to ASU 2016-01. This standard requires all equity investments (other than those accounted for under the equity method) to be measured at fair value with changes in the fair value recognized through net income. The Company recorded a $0.2 million cumulative-effect adjustment to the balance sheet upon adoption.

ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments ("ASU 2016-15"). On January 1, 2018, the Company adopted amendments to ASC 230 - Statement of Cash Flows ("ASC 230") on a retrospective basis pursuant to ASU 2016-15. This standard clarifies the treatment of several cash flow activities. ASU 2016-15 also clarifies that when cash receipts and cash payments have aspects of more than one classification of cash flows and cannot be separated, classification will depend on the predominant source or use. The adoption of this standard did not have a material impact on the Company's condensed consolidated financial statements.

ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash ("ASU 2016-18"). On January 1, 2018, the Company adopted amendments to ASC 230 on a retrospective basis pursuant to ASU 2016-18. This standard requires the inclusion of restricted cash with cash and cash equivalents when reconciling the beginning and ending cash on the statement of cash flows. Restricted cash includes cash pledged or on deposit with brokers of consolidated investment products. Cash, cash equivalents and restricted cash reported on the condensed consolidated statements of cash flows now includes $0.8 million, $1.1 million and $1.0 million of cash pledged or on deposit of consolidated investment products as of December 31, 2017, March 31, 2017, and December 31, 2016, respectively, as well as previously reported cash and cash equivalents. The adoption of this standard did not have a material impact on the Company's condensed consolidated financial statements.

ASU 2017-01, Clarifying the Definition of a Business ("ASU 2017-01"). On January 1, 2018, the Company adopted amendments to ASC 805 - Business Combinations ("ASC 805") and will apply the standard prospectively pursuant to ASU 2017-01. This standard provides guidance on evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The impact of ASU 2017-01 on the Company’s condensed consolidated financial statements will depend on acquisitions (or disposals) of assets or businesses by the Company in periods following adoption.

ASU 2017-04, Intangibles - Goodwill and Other: Simplifying the Accounting for Goodwill Impairment ("ASU 2017-04"). On January 1, 2018, the Company adopted amendments to ASC 350 - Intangibles Goodwill and Other and will apply the standard prospectively for all future annual and interim goodwill impairment tests pursuant to ASU 2017-04. Under ASU 2017-04, a goodwill impairment is defined to be the amount by which a reporting unit’s carrying value exceeds its fair value. The impact of the new standard on the Company’s condensed consolidated financial statements will depend on the outcomes of future goodwill impairment tests.

ASU 2018-05, Income Taxes (Topic 740), Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118 ("ASU 2018-05"). In March 2018, the Company adopted the amendments to ASC 740 - Income Taxes pursuant to ASU 2018-05. The standard adds various Securities and Exchange Commission ("SEC") paragraphs pursuant to the issuance of the December 2017 SEC Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act ("SAB 118"), which was effective immediately. The SEC issued SAB 118 to address concerns about reporting entities’ ability to timely comply with the accounting requirements to recognize all of the effects of the Tax Cuts and Jobs Act in the period of enactment. SAB 118 allows disclosure that timely determination of some or all of the income tax effects from the Tax Cuts and Jobs Act are incomplete by the due date of the financial statements and if possible to provide a reasonable estimate. We have accounted for the tax effects of the Tax Cuts and Jobs Act under the guidance of SAB 118, on a provisional basis. Our accounting for certain income tax effects is incomplete, but we have determined reasonable estimates for those effects and have recorded provisional amounts in our condensed consolidated financial statements as of March 31, 2018 and December 31, 2017.

New Accounting Standards Not Yet Implemented

In February 2018, the FASB issued ASU 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income ("ASU 2018-02"). The standard provides financial statement preparers with an option to reclassify stranded tax effects within accumulated other comprehensive income to retained earnings in each period in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Cuts and Jobs Act (or portion thereof) is recorded. ASU 2018-02 is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption is permitted. The Company does not expect the adoption of this guidance to have a material impact on the Company's condensed consolidated financial statements.

In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) ("ASU 2016-02"). The standard replaces current codification Topic 840 - Leases with updated guidance on accounting for leases and requires a lessee to recognize assets and liabilities arising from an operating lease on the balance sheet, whereas previous guidance did not require lease assets and liabilities to be recognized for most leases. Furthermore, this standard permits companies to make an accounting policy election to not recognize lease assets and liabilities for leases with a term of 12 months or less. For both finance leases and operating leases, the lease liability should be initially measured at the present value of the lease payments. The recognition, measurement and presentation of expenses and cash flows arising from a lease by a lessee will not significantly change under this new guidance. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018 and interim periods therein. Early adoption is permitted. The Company is currently evaluating the potential impact of this standard on its condensed consolidated financial statements but expects to record a right-of-use asset and a related lease obligation in the Company's condensed consolidated balance sheet upon adoption.