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Award Type Award Type [Axis] Treasury Stock Acquired, Average Cost Per Share Treasury Stock Acquired, Average Cost Per Share Income taxes payable Increase (Decrease) in Accrued Taxes Payable Subsequent Events [Abstract] Subsequent Events [Abstract] Gross Unrealized Losses Equity Securities, FV-NI, Unrealized Loss RELATED PARTY TRANSACTIONS Related Party Transactions Disclosure [Text Block] EXPENSES: Costs and Expenses [Abstract] Stock Repurchased During Period, Value Stock Repurchased During Period, Value Geographical [Axis] Geographical [Axis] Debt Securities, Trading Investments in trading securities Debt Securities, Trading Retained Earnings [Member] Retained Earnings [Member] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event [Line Items] Subsequent Event [Line Items] LEASES Lessee, Operating Leases [Text Block] Accrued purchase of property and equipment Capital Expenditures Incurred but Not yet Paid Document Period End Date Document Period End Date Weighted average shares outstanding: Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Statement [Table] Statement [Table] Other current assets Other Assets, Current Entity Registrant Name Entity Registrant Name Performance-based fees [Member] performance fee [Member] performance fee [Member] Cash dividends paid Payments of Dividends GOODWILL AND OTHER INTANGIBLE ASSETS Goodwill and Intangible Assets Disclosure [Text Block] Net fee revenues from external sources Revenue From External Sources Revenue From External Sources Total number of shares that may be issued under the stock based compensation Plan (including predecessor plans to the Plan) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Mutual Fund Share Incentive Awards Mutual Fund Share Incentive Awards [Member] Mutual Fund Share Incentive Awards Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Table Text Block] Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Table Text Block] Related Party Related Party [Domain] Share price Share Price Asia [Member] Asia [Member] Antidilutive Securities, Name Antidilutive Securities, Name [Domain] Retained earnings Retained Earnings (Accumulated Deficit) Purchases of treasury stock Amount of shares purchased in the open market Payments for Repurchase of Common Stock Scenario [Axis] Target [Axis] Target [Axis] Schedule Of Available For Sale Securities [Table] Schedule of Available-for-sale Securities [Table] Other Income Other Income Entity Tax Identification Number Entity Tax Identification Number Revenue [Policy Text Block] Revenue [Policy Text Block] Diluted (dollars per share) Earnings Per Share, Diluted Dilutive potential shares from unvested restricted shares (shares) Incremental Common Shares Attributable To Nonvested Restricted Shares Incremental common shares attributable to nonvested restricted shares. 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Europe [Member] Europe [Member] Schedule of Segment Reporting Information, by Segment [Table Text Block] Schedule of Segment Reporting Information, by Segment [Table Text Block] Segment Reporting [Abstract] Segment Reporting [Abstract] Westwood Funds® Westwood Funds [Member] Westwood funds. Intangible assets, net Finite-Lived Intangible Assets, Net Investment Income, Investment Expense Investment Income, Investment Expense Trust Trust [Member] Trust. Restricted Shares Subject to Service and Performance Conditions Restricted Shares Subject To Service And Performance Conditions [Member] Restricted shares subject to service and performance conditions. 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Trust Fees [Member] Trust Fee [Member] Trust Fee [Member] Purchase of treasury stock under employee stock plans (in shares) Treasury Stock, Shares, Acquired, Employee Stock Plan Treasury Stock, Shares, Acquired, Employee Stock Plan Variable Interest Entities [Abstract] Variable Interest Entities [Abstract] Variable interest entities. 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