Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2016
Description of Business and Significant Accounting Policies
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and include the accounts of the Company and its subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation. Amounts in the accompanying financial statements and notes are rounded to the nearest thousand unless otherwise stated. Certain amounts in the prior years’ financial statements have been reclassified for consistent presentation. The Company operates in one business segment as the Company’s management utilizes a consolidated approach to assess performance and allocate resources.
Consolidation	Consolidation In the normal course of our business, we sponsor and manage various types of investment products. These investment products include open-end mutual funds, a closed-end mutual fund, privately offered funds, exchange-traded managed funds, and a Luxembourg SICAV. When creating and launching a new investment product, we typically fund the initial cash investment, commonly referred to as “seeding,” so that the investment product can generate an investment performance track record so that it is able to attract third party investors in the product. Our initial investment in a new product typically represents 100% of the ownership in that product. We generally redeem our investment in seeded products when the related product establishes a sufficient track record, when third party investments in the related product are sufficient to sustain the strategy, or when a decision is made to no longer pursue the strategy. The length of time we hold a majority interest in a product varies based on a number of factors, including market demand, market conditions and investment performance. Our exposure to risk in these investment products is generally limited to any equity investment we have and any earned but uncollected management or other fund-related service fees. In accordance with financial accounting standards, we consolidate certain sponsored investment products in which we have a controlling interest or the investment product meets the criteria of a Variable Interest Entity (“VIE”) and we are deemed to be the primary beneficiary. In order to make this determination, an analysis is performed to determine if the investment product is a VIE or a Voting Interest Entity (“VOE”). Assessing if an entity is a VIE or VOE involves judgment and analysis on an entity by entity basis. Factors included in this assessment include the legal organization of the entity, the Company’s contractual involvement with the entity and any implications resulting from or associated with related parties’ involvement with the entity. A VIE is an entity which does not have adequate equity to finance its activities without subordinated financial support, the equity investors do not have the normal characteristics of equity investors for a potential controlling financial interest as a group, or the voting rights are not proportional to their obligations to absorb the expected losses or their rights to receive the expected residual returns of the entity. The Company is deemed to be the primary beneficiary if it absorbs a majority of the VIE’s expected losses, expected residual returns, or both. If the Company is the primary beneficiary of a VIE, we are required to consolidate the assets, liabilities, results of operations and cash flows of the VIE into our consolidated financial statements. If an entity does not meet the criteria and is not considered a VIE, it is treated as a VOE, which is subject to traditional consolidation concepts based on ownership rights. Sponsored investments products that are considered VOEs are consolidated if we have a controlling financial interest in the entity absent substantive investor rights to replace the investment manager of the entity (kick-out rights).
Use of Estimates	In the normal course of our business, we sponsor and manage various types of investment products. These investment products include open-end mutual funds, a closed-end mutual fund, privately offered funds, exchange-traded managed funds, and a Luxembourg SICAV. When creating and launching a new investment product, we typically fund the initial cash investment, commonly referred to as “seeding,” so that the investment product can generate an investment performance track record so that it is able to attract third party investors in the product. Our initial investment in a new product typically represents 100% of the ownership in that product. We generally redeem our investment in seeded products when the related product establishes a sufficient track record, when third party investments in the related product are sufficient to sustain the strategy, or when a decision is made to no longer pursue the strategy. The length of time we hold a majority interest in a product varies based on a number of factors, including market demand, market conditions and investment performance. Our exposure to risk in these investment products is generally limited to any equity investment we have and any earned but uncollected management or other fund-related service fees. In accordance with financial accounting standards, we consolidate certain sponsored investment products in which we have a controlling interest or the investment product meets the criteria of a Variable Interest Entity (“VIE”) and we are deemed to be the primary beneficiary. In order to make this determination, an analysis is performed to determine if the investment product is a VIE or a Voting Interest Entity (“VOE”). Assessing if an entity is a VIE or VOE involves judgment and analysis on an entity by entity basis. Factors included in this assessment include the legal organization of the entity, the Company’s contractual involvement with the entity and any implications resulting from or associated with related parties’ involvement with the entity. A VIE is an entity which does not have adequate equity to finance its activities without subordinated financial support, the equity investors do not have the normal characteristics of equity investors for a potential controlling financial interest as a group, or the voting rights are not proportional to their obligations to absorb the expected losses or their rights to receive the expected residual returns of the entity. The Company is deemed to be the primary beneficiary if it absorbs a majority of the VIE’s expected losses, expected residual returns, or both. If the Company is the primary beneficiary of a VIE, we are required to consolidate the assets, liabilities, results of operations and cash flows of the VIE into our consolidated financial statements. If an entity does not meet the criteria and is not considered a VIE, it is treated as a VOE, which is subject to traditional consolidation concepts based on ownership rights. Sponsored investments products that are considered VOEs are consolidated if we have a controlling financial interest in the entity absent substantive investor rights to replace the investment manager of the entity (kick-out rights). Use of Estimates GAAP requires us to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses in the consolidated financial statements and accompanying notes, and related disclosures of commitments and contingencies. Estimates are used for, but are not limited to, depreciation and amortization, income taxes, valuation of assets, pension and postretirement obligations, and contingencies. Management evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors, including the current economic environment. Actual results could differ from our estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents include cash on hand and short‑term investments. We consider all highly liquid investments with maturities upon acquisition of 90 days or less to be cash equivalents. Cash and cash equivalents – restricted represents cash held for the benefit of customers and non-customers segregated in compliance with federal and other regulations.
Disclosures About Fair Value of Financial Instruments	Disclosures About Fair Value of Financial Instruments Fair value of cash and cash equivalents, receivables and payables approximates carrying value. Fair value of long‑term debt is disclosed in Note 7. Fair values for investment securities are based on quoted market prices, where available. Otherwise, fair values for investment securities are based on Level 2 or Level 3 inputs detailed in Note 3.
Investment Securities and Investments in Sponsored Funds	Investment Securities and Investments in Sponsored Funds Our investments are comprised of United States, government obligations, investments in sponsored funds and sponsored privately offered funds. Sponsored funds, which include the 1940 Act Mutual Funds, IVH, the IGI Funds and the LLCs, are investments we have made for both general corporate investment purposes and to provide seed capital for new investment products. The Company has classified its investments in certain sponsored funds as either equity method investments (when the Company owns between 20% and 50% of the fund) or as available for sale investments (when the Company owns less than 20% of the fund) as described in Note 3. Investments held by our broker-dealer entities or certain investments that are anticipated to be purchased and sold on a more frequent basis are classified as trading. Unrealized holding gains and losses on securities available for sale, net of related tax effects, are excluded from earnings until realized and are reported as a separate component of comprehensive income. For trading securities, unrealized holding gains and losses are included in earnings. Realized gains and losses are computed using the specific identification method for investment securities, other than sponsored funds. For sponsored funds, realized gains and losses are computed using the average cost method. Substantially all of the Company’s equity method investees are investment companies which record their underlying investments at fair value. Therefore, under the equity method of accounting, our share of the investee's underlying net income or loss is predominantly representative of fair value adjustments in the investments held by the equity method investee. Our share of the investee's net income or loss is based on the most current information available and is recorded as a net gain or loss on investments within investment and other income (loss). Our available for sale investments are reviewed each quarter and adjusted for other than temporary declines in value. We consider factors affecting the issuer and the industry in which the issuer operates, general market trends including interest rates, and our ability and intent to hold an investment until it has recovered. Consideration is given to the length of time an investment’s market value has been below carrying value as well as prospects for recovery to carrying value. When a decline in the fair value of equity securities is determined to be other than temporary, the unrealized loss recorded net of tax in other comprehensive income is realized as a charge to net income, and a new cost basis is established. When a decline in the fair value of debt securities is determined to be other than temporary, the amount of the impairment recognized in earnings depends on whether the Company intends to sell the security or more likely than not will be required to sell the security before recovery of its amortized cost basis less any current‑period credit loss. If so, the other than temporary impairment recognized in earnings is equal to the entire difference between the investment’s amortized cost basis and its fair value at the balance sheet date. If not, the portion of the impairment related to the credit loss is recognized in earnings while the portion of the impairment related to other factors is recognized in other comprehensive income, net of tax.
Property and Equipment	Property and Equipment Property and equipment are carried at cost. The costs of improvements that extend the life of a fixed asset are capitalized, while the costs of repairs and maintenance are expensed as incurred. Depreciation and amortization are calculated and recorded using the straight‑line method over the estimated useful life of the related asset (or lease term if shorter), generally three to 10 years for furniture and fixtures; one to 10 years for computer software; one to five years for data processing equipment; one to 30 years for buildings; two to 26 years for other equipment; and up to 15 years for leasehold improvements, which is the lesser of the lease term or expected life.
Software Developed for Internal Use	Software Developed for Internal Use Certain internal costs incurred in connection with developing or obtaining software for internal use are capitalized in accordance with ASC 350, “Intangibles – Goodwill and Other Topic.” Internal costs capitalized are included in property and equipment, net in the consolidated balance sheets, and were $13.3 million and $13.9 million as of December 31, 2016 and 2015, respectively. Amortization begins when the software project is complete and ready for its intended use and continues over the estimated useful life, generally one to 10 years.
Goodwill and Identifiable Intangible Assets	Goodwill and Identifiable Intangible Assets Goodwill represents the excess of cost over fair value of the identifiable net assets of acquired companies. Indefinite-lived intangible assets represent advisory and subadvisory management contracts for managed assets obtained in acquisitions. The Company considers these contracts to be indefinite-lived intangible assets as they are expected to be renewed without significant cost or modification of terms. Goodwill and indefinite-lived intangible assets are tested for impairment annually or more frequently if events or circumstances indicate that the carrying value may not be recoverable. Goodwill and intangible assets require significant management estimates and judgment, including the valuation determination in connection with the initial purchase price allocation and the ongoing evaluation for impairment. Additional information related to the indefinite-lived intangible assets is included in Note 6.
Deferred Sales Commissions	Deferred Sales Commissions We defer certain costs, principally sales commissions and related compensation, which are paid to financial advisors and broker-dealers in connection with the sale of certain mutual fund shares sold without a front-end load sales charge. The costs incurred at the time of the sale of Class B shares sold prior to January 1, 2014 are amortized on a straight-line basis over five years, which approximates the expected life of the shareholders’ investments. Effective January 1, 2014, the Company suspended sales of Class B shares. The costs incurred at the time of the sale of Class C shares are amortized on a straight-line basis over 12 months. Prior to June 16, 2014, the costs incurred at the time of the sale of shares for certain fee-based asset allocation products were deferred and amortized on a straight-line basis, not to exceed three years. We recover deferred sales commissions and related compensation through Rule 12b-1 and other distribution fees, which are paid on the Class B and Class C shares of the Advisors Funds and Ivy Funds, along with CDSCs paid by shareholders who redeem their shares prior to completion of the specified holding period (three years for shares of certain fee-based asset allocation products sold prior to June 16, 2014, six years for a Class B share and 12 months for a Class C share), as well as through client fees paid on the asset allocation products sold prior to June 16, 2014. Effective June 16, 2014 we no longer assess a CDSC to investors upon early redemption of fee-based asset allocation products and amounts deferred for sales commissions and related compensation are classified in the prepaid and other current asset and other non-current assets in our consolidated balance sheet. Should we lose our ability to recover deferred sales commissions through distribution fees or CDSCs, the value of these assets would immediately decline, as would future cash flows. We periodically review the recoverability of the deferred sales commission assets as events or changes in circumstances indicate that their carrying amount may not be recoverable and adjust them accordingly. Impairment adjustments are recognized in operating income as a component of amortization of deferred sales commissions.
Revenue Recognition	Revenue Recognition Investment Management and Advisory Fees We recognize investment management fees as earned over the period in which services are rendered. We charge the Funds daily based upon average daily net assets under management in accordance with investment management agreements between the Funds and the Company. The majority of investment and/or advisory fees earned from the IGI Funds and from institutional and separate accounts are charged either monthly or quarterly based upon an average of net assets under management in accordance with such investment management agreements. The Company may waive certain fees for investment management services at its discretion, or in accordance with contractual expense limitations, and these waivers are reflected as a reduction to investment management fees on the consolidated statements of income. Our investment advisory business receives research products and services from broker-dealers through “soft dollar” arrangements. Consistent with the “soft dollar” safe harbor established by Section 28(e) of the Securities Exchange Act of 1934, as amended, the investment advisory business does not have any contractual obligation requiring it to pay for research products and services obtained through soft dollar arrangements with brokers. As a result, we present “soft dollar” arrangements on a net basis. The Company has contractual arrangements with third parties to provide subadvisory services. Investment advisory fees are recorded gross of any subadvisory payments and are included in investment management fees based on management’s determination that the Company is acting in the capacity of principal service provider with respect to its relationship with the Funds. Any corresponding fees paid to subadvisors are included in operating expenses. Distribution, Underwriter and Shareholder Service Fees Underwriting and distribution commission revenues resulting from the sale of investment products are recognized on the trade date. When a client purchases Class A or Class E shares (front-end load), the client pays an initial sales charge of up to 5.75% of the amount invested. The sales charge for Class A or Class E shares typically declines as the investment amount increases. In addition, investors may combine their purchases of all fund shares to qualify for a reduced sales charge. When a client invests in a fee-based asset allocation product, Class I or Y shares are purchased at net asset value, and we do not charge an initial sales charge. Under a Rule 12b-1 service plan, the Funds may charge a maximum fee of 0.25% of the average daily net assets under management for Class B, C, E and Ivy Funds Y shares for expenses paid to broker-dealers and other sales professionals in connection with providing ongoing services to the Funds’ shareholders and/or maintaining the Funds’ shareholder accounts, with the exception of the Funds’ Class R shares, for which the maximum fee is 0.50% and for the Class I, R6 and Advisors Funds Y shares, which do not charge a service fee. The Funds’ Class B and Class C shares may charge a maximum of 0.75% of the average daily net assets under management under a Rule 12b-1 distribution plan to broker-dealers and other sales professionals for their services in connection with distributing shares of that class. The Funds’ Class A shares may charge a maximum fee of 0.25% of the average daily net assets under management under a Rule 12b-1 service and distribution plan for expenses detailed previously. The Rule 12b-1 plans are subject to annual approval by the Funds’ board of trustees, including a majority of the disinterested members, by votes cast in person at a meeting called for the purpose of voting on such approval. All Funds may terminate the service and distribution plans at any time with approval of fund trustees or portfolio shareholders (a majority of either) without penalty. Fee‑based asset allocation revenues are charged monthly based upon average daily net assets under management. For certain types of investment products, primarily variable annuities, distribution revenues are generally calculated based upon average daily net assets under management and are recognized monthly. Fees collected from financial advisors for services related to technology and errors and omissions insurance are recorded in underwriting and distribution fees on a gross basis, as the Company is the primary obligor in these arrangements. Shareholder service fees are recognized monthly and are calculated based on the number of accounts or assets under management as applicable. Other administrative service fee revenues are recognized when contractual obligations are fulfilled or as services are provided.
Advertising and Promotion	Advertising and Promotion We expense all advertising and promotion costs as the advertising or event takes place. Advertising expense was $9.4 million, $15.7 million and $15.7 million for the years ended December 31, 2016, 2015 and 2014, respectively, and is classified in both underwriting and distribution expense and general and administrative expense in the consolidated statements of income.
Leases	Leases The Company leases office space under various leasing arrangements. Most lease agreements contain renewal options, rent escalation clauses and/or other inducements provided by the landlord. As leases expire, they are typically renewed or replaced in the ordinary course of business. Rent expense is recorded on a straight-line basis, including escalations and inducements, over the term of the lease.
Share-Based Compensation	Share‑Based Compensation We account for share‑based compensation expense using the fair value method. Under the fair value method, share‑based compensation expense reflects the fair value of share‑based awards measured at grant date, is recognized over the service period, and is adjusted each period for anticipated forfeitures. The Company also issues share‑based awards to our financial advisors, who are independent contractors, and to our Board of Directors. Changes in the Company’s share price result in variable compensation expense over the vesting period of awards granted to our financial advisors and Board of Directors.
Accounting for Income Taxes	Accounting for Income Taxes Income tax expense is based on pre-tax financial accounting income, including adjustments made for the recognition or derecognition related to uncertain tax positions. The recognition or derecognition of income tax expense related to uncertain tax positions is determined under the guidance as prescribed by “Income Taxes Topic,” ASC 740. Deferred tax assets and liabilities are recognized for the future tax attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis. A valuation allowance is recognized for deferred tax assets if, based on available evidence, it is more likely than not that all or some portion of the asset will not be realized. Deferred tax assets and liabilities are measured using enacted tax rates expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in earnings in the period that includes the enactment date.