Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] 2014 Equity and Cash Incentive Plan Equity and Cash Incentive Plan [Member] 2011 equity and cash incentive plan. Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Common shares available for issuance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Deferred compensation equity Deferred Compensation Equity Fully vested employee elected deferral period Deferred Compensation Arrangement, Fully Vested Employee Elected Deferral Period Deferred Compensation Arrangement, Fully Vested Employee Elected Deferral Period Deferred compensation liability Deferred Compensation Liability, Current and Noncurrent Compensation Plans Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Earnings Per Share [Abstract] Earnings Per Share Earnings Per Share [Text Block] Subsequent Events [Abstract] Subsequent Events Subsequent Events [Text Block] Debt Disclosure [Abstract] Line of Credit Debt Disclosure [Text Block] Accounting Policies [Abstract] Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Reclassification Reclassification, Policy [Policy Text Block] Principles of Consolidation Consolidation, Policy [Policy Text Block] Redeemable Noncontrolling Interest Consolidation, Subsidiaries or Other Investments, Consolidated Entities, Policy [Policy Text Block] Segment Information Segment Reporting, Policy [Policy Text Block] Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Accounts Receivable Receivables, Policy [Policy Text Block] Investments Investment, Policy [Policy Text Block] Fair Value Measurements Fair Value Measurement, Policy [Policy Text Block] Property and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Revenue Recognition - General Revenue Recognition, Policy [Policy Text Block] Revenue Recognition - Variable Incentive Revenue Revenue Recognition, Services, Management Fees [Policy Text Block] Revenue Recognition - Mutual Fund Administration Revenue Recognition Accounting Policy, Gross and Net Revenue Disclosure [Policy Text Block] Income Taxes Income Tax, Policy [Policy Text Block] Earnings Per Share Earnings Per Share, Policy [Policy Text Block] Recently Issued Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] Investments, Debt and Equity Securities [Abstract] Fair value of investment Investments, Fair Value Disclosure Trading Securities [Table] Trading Securities [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Total Parent [Member] Redeemable Noncontrolling Interest Noncontrolling Interest [Member] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Domain] Major Types of Debt and Equity Securities [Domain] Securities held in Consolidated Funds Securities held in Consolidated Funds [Member] Securities held in Consolidated Funds [Member] Schedule of Trading Securities and Other Trading Assets [Line Items] Schedule of Trading Securities and Other Trading Assets [Line Items] Trading Investments Trading Securities Line of Credit Facility [Table] Line of Credit Facility [Table] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] The Credit Agreement The Credit Agreement [Member] The Credit Agreement [Member] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Line of Credit Line of Credit [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] London Interbank Offered Rate (LIBOR) London Interbank Offered Rate (LIBOR) [Member] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Line of credit, remaining borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Line of credit, interest rate description Debt Instrument, Basis Spread on Variable Rate Line of credit, unused capacity, commitment fee percentage Line of Credit Facility, Unused Capacity, Commitment Fee Percentage Statement of Financial Position [Abstract] ASSETS Assets [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Investment portfolio Investments Accounts receivable Accounts Receivable, Net Prepaid expenses Prepaid Expense Income taxes receivable Income Taxes Receivable, Current Property and equipment, net of depreciation Property, Plant and Equipment, Net Deferred taxes Deferred Tax Assets, Net of Valuation Allowance Total assets Assets LIABILITIES AND SHAREHOLDERS’ EQUITY Liabilities and Equity [Abstract] Liabilities Liabilities [Abstract] Accounts payable and accrued expenses Accounts Payable and Accrued Liabilities Accrued incentive compensation Accrued Bonuses, Current Deferred compensation Total liabilities Liabilities Redeemable noncontrolling interest Redeemable Noncontrolling Interest, Equity, Common, Fair Value Shareholders’ equity Stockholders' Equity Attributable to Parent [Abstract] Common stock, no par value 7,000,000 shares authorized; 3,468,565 issued and outstanding at September 30, 2017 (inclusive of 203,650 unvested shares); 3,411,556 issued and outstanding at December 31, 2016 (inclusive of 201,800 unvested shares) Common Stock, Value, Issued Preferred stock, undesignated, 1,000,000 shares authorized and unissued Preferred Stock, Value, Issued Deferred equity compensation Retained earnings Retained Earnings (Accumulated Deficit) Total shareholders’ equity Stockholders' Equity Attributable to Parent Total liabilities and shareholders’ equity Liabilities and Equity Book value per share (usd per share) Book Value Per Share Book value per share is computed by dividing total shareholders' equity by the number of shares issued and outstanding at the end of the measurement period. Significant Accounting Policies Significant Accounting Policies [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Business and Organization Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Equity Method Investments [Abstract] Equity Method Investments [Abstract] Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Table] Investment Type [Axis] Investment Type [Axis] Investments [Domain] Investments [Domain] High Yield Fund High Yield Fund [Member] High Yield Fund Research Opportunities Fund Research Opportunities Fund [Member] Research opportunities fund. Global Fund LP Global Fund LP [Member] Global Fund LP International Equity Fund LP International Equity Fund LP [Member] International Equity Fund LP Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Equity Method Investment, Ownership Percentage Equity Method Investment, Ownership Percentage Discontinued Operations and Disposal Groups [Abstract] Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Disposal Group Classification [Axis] Disposal Group Classification [Axis] Disposal Group Classification [Domain] Disposal Group Classification [Domain] Disposal Group, Disposed of by Sale, Not Discontinued Operations Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] Disposal Group Name [Axis] Disposal Group Name [Axis] Disposal Group Name [Domain] Disposal Group Name [Domain] Beacon Hill Beacon Hill [Member] Beacon Hill [Member] Promissory Note Promissory Note [Member] Promissory Note [Member] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Cash consideration received net of cash disposed Proceeds from Divestiture of Businesses, Net of Cash Divested Contingent consideration received Disposal Group, Including Discontinued Operation, Contingent Consideration Disposal Group, Including Discontinued Operation, Contingent Consideration Proceeds from collection of notes receivable Proceeds from Collection of Notes Receivable Restricted Stock Units (RSUs) Restricted Stock Units (RSUs) [Member] 2017 (Remaining Period) Employee Service Share Based Compensation Nonvested Awards Compensation Cost Not Yet Recognized Current Employee service share based compensation nonvested awards compensation cost not yet recognized current. 2018 Employee Service Share Based Compensation Nonvested Awards Compensation Cost Not Yet Recognized in Year One Employee service share based compensation nonvested awards compensation cost not yet recognized in year one. 2019 Employee Service Share Based Compensation Nonvested Awards Compensation Cost Not Yet Recognized in Year Two Employee service share based compensation nonvested awards compensation cost not yet recognized in year two. 2020 Employee Service Share Based Compensation Nonvested Awards Compensation Cost Not Yet Recognized in Year Three Employee service share based compensation nonvested awards compensation cost not yet recognized in year three. 2021 Employee Service Share Based Compensation Nonvested Awards Compensation Cost Not Yet Recognized in Year Four Employee service share based compensation nonvested awards compensation cost not yet recognized in year four Thereafter Employee Service Share Based Compensation Nonvested Awards Compensation Cost Not Yet Recognized in Year Five Employee service share based compensation nonvested awards compensation cost not yet recognized in year five. Total Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Leases [Abstract] Remainder of 2017 Operating Leases, Future Minimum Payments, Remainder of Fiscal Year 2018 Operating Leases, Future Minimum Payments, Due in Two Years 2019 Operating Leases, Future Minimum Payments, Due in Three Years 2020 Operating Leases, Future Minimum Payments, Due in Four Years 2021 Operating Leases, Future Minimum Payments, Due in Five Years Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Total future lease payments due Operating Leases, Future Minimum Payments Due Subsequent Event [Table] Subsequent Event [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Dividends declared (in usd per share) Common Stock, Dividends, Per Share, Declared Dividends to be paid in cash Dividends, Common Stock, Cash Mutual fund administration: Mutual Fund Administration [Abstract] Mutual fund administration. Administration revenue, gross Administrative Services Revenue 12b-1/service fees and commission revenue received from fund clients Fees and Commissions 12b-1/service fees and commission expense payments to third parties Service Fees and Commission Expense Payments to Third Parties Service fees and commission expense payments to third parties. Fund related expense Fund Related Expense Fund related expense. Revenue, net of related expenses Revenue from Administrative Services Excluding Financial Activity Net Revenue from administrative services excluding financial activity net. DHCM C-Share financing: Share Financing [Abstract] DHCM C-Share financing. Broker commission advance repayments Broker Commission Advance Repayments Broker commission advance repayments. Broker commission amortization Broker Commission Amortization Broker commission amortization. Financing activity, net Financing Activity Net Financing activity, net. Mutual fund administration revenue, net Revenue from Administrative Services Net Revenue from administrative services net. Business Organization And Significant Accounting Policies [Table] Business Organization And Significant Accounting Policies [Table] Business Organization And Significant Accounting Policies [Table] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Affiliated Entity Affiliated Entity [Member] Parent Related Party Transaction [Axis] Related Party Transaction [Axis] Related Party Transaction [Domain] Related Party Transaction [Domain] Investment advisory and fund administration services Investment Advisory And Fund Administration Services [Member] Investment Advisory And Fund Administration Services [Member] Mutual fund administrative services Mutual Fund Administrative Services [Member] Mutual fund administrative services [Member] Money Market Funds Money Market Funds [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Fair Value, Inputs, Level 1 Fair Value, Inputs, Level 1 [Member] Business Organization And Significant Accounting Policies [Line Items] Business Organization And Significant Accounting Policies [Line Items] Business Organization And Significant Accounting Policies [Line Items] Number of business segment Number of Operating Segments Allowance for doubtful accounts Allowance for Doubtful Accounts Receivable Accounts receivable, related parties Accounts Receivable, Related Parties Cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Transfers between fair value levels Fair Value, Transfers Between Level 1, Level 2, or Level 3, Amount Fair Value, Transfers Between Level 1, Level 2, or Level 3, Amount Revenue from related parties Revenue from Related Parties Client performance period Rolling Client Investment Performance Period Rolling Client Investment Performance Period Variable fees Performance Fees Advance commissions amortization period Advance Commissions Amortization Period Advance commissions amortization period. Liability for uncertain tax positions Liability for Uncertainty in Income Taxes, Current Investment Holdings [Table] Investment Holdings [Table] Company sponsored investments Seed Capital Investments [Member] Seed Capital Investments [Member] Redeemable Noncontrolling Interest Investment Holdings [Line Items] Investment Holdings [Line Items] Trading investments Company sponsored equity method investments Equity Method Investments Total Investment portfolio Area of operating lease Lessee Leasing Agreements, Operating Leases, Area under Lease Lessee Leasing Agreements, Operating Leases, Area under Lease Number of office space locations Lessee Leasing Agreements, Operating Leases, locations Lessee Leasing Agreements, Operating Leases, locations Operating lease expense excluding rent Operating Lease Expense Excluding Rent Operating Lease Expense Excluding Rent Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Common Stock Common Stock [Member] Deferred Equity Compensation Deferred Compensation, Share-based Payments [Member] Retained Earnings Retained Earnings [Member] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning balance (shares) Common Stock, Shares, Outstanding Beginning Balance Issuance of restricted stock grants (shares) Stock Issued During Period, Shares, Restricted Stock Award, Gross Issuance of restricted stock grants Stock Issued During Period, Value, Restricted Stock Award, Gross Amortization of restricted stock grants Amortization Of Restricted Stock Grants Amortization of restricted stock grants. Issuance of stock grants (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Issuance of stock grants Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Issuance of common stock related to 401k plan match (shares) Stock Issued During Period, Shares, New Issues Issuance of common stock related to 401k plan match Stock Issued During Period, Value, New Issues Shares withheld related to employee tax withholding (shares) Shares Paid for Tax Withholding for Share Based Compensation Shares withheld related to employee tax withholding Adjustments Related to Tax Withholding for Share-based Compensation Forfeiture of restricted stock grants (shares) Stock Issued During Period, Shares, Restricted Stock Award, Forfeited Forfeiture of restricted stock grants Stock Issued During Period, Value, Restricted Stock Award, Forfeitures Net Income (Loss) Attributable to Parent Net Income (Loss) Attributable to Parent Ending balance (shares) Ending Balance Increase (Decrease) in Temporary Equity [Roll Forward] Increase (Decrease) in Temporary Equity [Roll Forward] Beginning balance attributable to redeemable noncontrolling Interests Redeemable Noncontrolling Interest, Equity, Carrying Amount Net Income Attributable to Redeemable Noncontrolling Interest Net Income (Loss) Attributable to Redeemable Noncontrolling Interest Net subscriptions of consolidated funds Subscription From Redemption Distribution To Noncontrolling Interest A positive value represents subscriptions net of redemptions and distributions to redeemable non-controlling interest holders. A negative value represents redemptions and distributions paid to redeemable non-controlling interest holders net of subscriptions received. Ending balance attributable to redeemable noncontrolling Interests Principal Transaction Revenue [Table] Principal Transaction Revenue [Table] Principal Transaction Revenue, Description of Reporting Category [Axis] Principal Transaction Revenue, Description of Reporting Category [Axis] Name of Reporting Category [Domain] Name of Reporting Category [Domain] Quarter Ended December 31, 2018 Asset Under Management Contractual Period End Date [Member] Asset under management contractual period end date. Quarter Ended September 30, 2019 Asset Under Management Contractual Period End Date 2 [Member] Asset Under Management Contractual Period End Date 2 [Member] Quarter Ended March 31, 2020 Asset Under Management Contractual Period End Date 3 [Member] Asset Under Management Contractual Period End Date 3 [Member] Quarter Ended September 30, 2021 Asset Under Management Contractual Period End Date 4 [Member] Asset Under Management Contractual Period End Date 4 [Member] Total Asset Under Management Contractual Period End Total [Member] Asset Under Management Contractual Period End Total Principal Transaction Revenue [Line Items] Principal Transaction Revenue [Line Items] AUM subject to variable fees Assets Under Management Variable Performance Fees Assets under management (AUM) subject to variable performance fees and variable performance fees. Unearned variable fees Potential Variable Fees Based Upon Current Investment Results Potential Variable Fees Based Upon Current Investment Results Summary of Market Value of Investments Summary Investment Holdings [Table Text Block] Equity Method Investments Equity Method Investments [Table Text Block] Shares Issued Shares Outstanding [Member] Shares outstanding. Grant Date Value Shares issued (shares) Income Statement [Abstract] REVENUES: Revenues [Abstract] Investment advisory Investment Advisory Fees Mutual fund administration, net Total revenue Revenues OPERATING EXPENSES: Operating Expenses [Abstract] Compensation and related costs Labor and Related Expense General and administrative General and Administrative Expense Sales and marketing Selling and Marketing Expense Mutual fund administration Asset Management Costs Total operating expenses Operating Expenses NET OPERATING INCOME Operating Income (Loss) Investment income, net Investment Income, Net Gain on sale of subsidiary Gain (Loss) on Disposition of Business INCOME BEFORE TAXES Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Income tax expense Income Tax Expense (Benefit) NET INCOME Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Less: Net income attributable to redeemable noncontrolling interest Net Income (Loss) Attributable to Noncontrolling Interest NET INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS Earnings per share attributable to common shareholders Basic (USD per share) Earnings Per Share, Basic Diluted (USD per share) Earnings Per Share, Diluted Weighted average shares outstanding Weighted Average Number of Shares Outstanding, Diluted [Abstract] Basic (in shares) Weighted Average Number of Shares Outstanding, Basic Diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Net Income Dilutive impact of restricted stock units (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Diluted (in shares) Earnings per share Earnings Per Share, Basic and Diluted [Abstract] Sale of Beacon Hill Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Roll-Forward of Outstanding Restricted Stock Grants Issued Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block] Expense Recognition of Deferred Compensation Schedule of Expense Recognition of Deferred Compensation Arrangement [Table Text Block] Schedule of expense recognition of deferred compensation arrangement. Schedule of Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Grant Date Intrinsic Value Schedule of Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Grant Date Intrinsic Value [Table Text Block] Operating Leases Leases of Lessee Disclosure [Text Block] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair Value, Measurements, Recurring Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 3 Fair Value, Inputs, Level 3 [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Common stock, par value (usd per share) Common Stock, No Par Value Common stock, shares authorized Common Stock, Shares Authorized Common stock, shares issued Common Stock, Shares, Issued Common stock, shares outstanding Preferred stock, shares authorized Preferred Stock, Shares Authorized Preferred stock, shares issued Preferred Stock, Shares Issued Preferred Stock, shares Outstanding Preferred Stock, Shares Outstanding Unvested shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Fair Value Measurements, Recurring and Nonrecurring Fair Value Measurements, Recurring and Nonrecurring [Table Text Block] Assets under Management (AUM) Subject to Incentive Fees and Incentive Fees Assets Under Management Variable Performance Fees [Table Text Block] Assets under management (AUM) subject to variable performance fees and variance performance fees. Mutual Fund Administration Gross and Net Revenue Mutual Fund Administration Gross and Net Revenue [Table Text Block] Mutual fund administration gross and net revenue. Investment Portfolio Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Summary of Total Lease and Operating Expenses Lessee, Operating Lease, Disclosure [Table Text Block] Future Minimum Lease Payments under Operating Leases Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Brokers and Dealers [Abstract] Regulatory Capital Requirements [Abstract] Shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Outstanding shares, Beginning Balance (shares) Grants vested (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Grants forfeited (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Outstanding shares, Ending Balance (shares) Weighted-Average Grant Date Price per Share Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Weighted-Average Grant Date Price per Share, Beginning of Period (usd per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Weighted-Average Grant Date Price per Share, Grants issued (usd per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Weighted-Average Grant Date Price per Share, Grants vested (usd per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Weighted-Average Grant Date Price per Share, Grants forfeited (usd per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Weighted-Average Grant Date Price per Share, End of Period (usd per share) Computation for Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Income Tax Disclosure [Abstract] Income Taxes Income Tax Disclosure [Text Block] Document and Entity Information [Abstract] Document and Entity Information [Abstract] Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Statement of Cash Flows [Abstract] CASH FLOWS FROM OPERATING ACTIVITIES: Net Cash Provided by (Used in) Operating Activities [Abstract] Net Income Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation Depreciation Share-based compensation Share-based Compensation Decrease in accounts receivable Increase (Decrease) in Accounts Receivable Change in current income taxes Increase (Decrease) in Income Taxes Payable Change in deferred income taxes Increase (Decrease) in Deferred Income Taxes Gain on sale of subsidiary Net gains on investments Gain (Loss) on Investments Net change in trading securities held by Consolidated Funds Increase (Decrease) in Trading Securities Decrease (increase) in accrued incentive compensation Increase (Decrease) in Employee Related Liabilities Increase in deferred compensation Increase (Decrease) in Deferred Compensation Excess income tax benefit from share-based compensation Excess Tax Benefit from Share-based Compensation, Operating Activities Income tax benefit from dividends paid on restricted stock Income Tax Benefit From Dividends Paid On Restricted Stock Operating Activities Income tax benefit from dividends paid on restricted stock. Other changes in assets and liabilities Increase (Decrease) in Other Operating Assets and Liabilities, Net Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities CASH FLOWS FROM INVESTING ACTIVITIES: Net Cash Provided by (Used in) Investing Activities [Abstract] Purchase of property and equipment Payments to Acquire Property, Plant, and Equipment Purchase of Company sponsored investments Payments to Acquire Investments Proceeds from sale of Company sponsored investments Proceeds from Sale, Maturity and Collection of Investments Proceeds from sale of subsidiary, net of cash disposed Net cash provided by (used in) investing activities Net Cash Provided by (Used in) Investing Activities CASH FLOWS FROM FINANCING ACTIVITIES: Net Cash Provided by (Used in) Financing Activities [Abstract] Value of shares withheld related to employee tax withholding Payments Related to Tax Withholding for Share-based Compensation Excess income tax benefit from share-based compensation Excess Tax Benefit from Share-based Compensation, Financing Activities Income tax benefit from dividends paid on restricted stock Income Tax Benefit From Dividends Paid On Restricted Stock Financing Activities Income tax benefit from dividends paid on restricted stock. Net subscriptions received from redeemable noncontrolling interest holders Proceeds from (Payments to) Noncontrolling Interests Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities CASH AND CASH EQUIVALENTS Cash and Cash Equivalents, at Carrying Value [Abstract] Net change during the period Cash and Cash Equivalents, Period Increase (Decrease) At beginning of period At end of period Supplemental cash flow information: Supplemental Cash Flow Information [Abstract] Income taxes paid Income Taxes Paid Supplemental disclosure of non-cash transactions: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Common stock issued as incentive compensation Charitable donation of corporate investments and property and equipment Contribution of Investments and Property and Equipment Value of investments and property and equipment contributed in noncash investing and financing activities. Cumulative-effect adjustment from the adoption of ASU 2015-02 (Note 2) New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification Net issuance (redemption) of ETF shares for marketable securities Net issuance of ETF shares for marketable securities Value of ETF shares issued in exchange for marketable securities. Total assets Equity Method Investment, Summarized Financial Information, Assets Total liabilities Equity Method Investment, Summarized Financial Information, Liabilities Net assets Equity Method Investment Summarized Financial Information, Equity DHCM's portion of net assets Equity Method Investment, Underlying Equity in Net Assets Investment Income Equity Method Investment, Summarized Financial Information, Revenue Expenses Equity Method Investment, Summarized Financial Information, Expenses The amount of expenses reported by an equity method investment of the entity. Net realized gains (losses) Equity Method Investment, Summarized Financial Information, Net realized gains (losses) The amount of net realized gains (losses) reported by an equity method investment of the entity. Net change in unrealized appreciation/depreciation Equity Method Investment, Summarized Financial Information, Net change in unrealized appreciation/depreciation The amount of net change in unrealized appreciation/depreciation reported by an equity method investment of the entity. Net income Equity Method Investment, Summarized Financial Information, Net Income (Loss) DHCM's portion of net income Income (Loss) from Equity Method Investments Lease and operating expenses Operating Leases, Rent Expense, Net Income tax expense (benefit) Effective tax rate Effective Income Tax Rate Reconciliation, Percent Federal statutory income tax rate, percent Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Effective income tax rate reconciliation, share-based compensation, excess tax benefit (tax shortfall), Amount Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit (Tax Shortfall), Amount Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit (Tax Shortfall), Amount Effective income tax rate reconciliation, tax benefit due to donation of appreciated securities, Amount Effective Income Tax Rate Reconciliation, Tax Benefit Due To Donation Of Appreciated Securities, Amount Effective Income Tax Rate Reconciliation, Tax Benefit Due To Donation Of Appreciated Securities, Amount Income tax effects allocated directly to equity Income Tax Effects Allocated Directly to Equity Valuation allowance Deferred Tax Assets, Valuation Allowance