Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Apr. 02, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity available-for-sale securities	$ 10,218		$ 11,250
Fixed income available-for-sale securities	101,683		76,733
Fixed income securities owned	30,892		21,526
Investment funds sponsored by LSV	4,887		6,034
Assets, fair value	147,680		115,543
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity available-for-sale securities	10,218		11,250
Fixed income available-for-sale securities	0		0
Fixed income securities owned	0		0
Assets, fair value	10,218		11,250
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity available-for-sale securities	0		0
Fixed income available-for-sale securities	101,683		76,733
Fixed income securities owned	30,892		21,526
Assets, fair value	$ 132,575		$ 98,259
Huntington Steele, LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent purchase price		$ 12,120
Huntington Steele, LLC \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent purchase price		$ 12,120

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of equity securities categorized neither as held-to-maturity nor as trading.

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The amount of liability arising from an inherited contingency (as defined) which has been recognized as of the acquisition date.

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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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The fair value as of the balance sheet date of firm holdings in debt obligations issued by the US government including short-term Treasury bills, medium-term Treasury notes, and long-term Treasury bonds, as well as debt issued by agencies. Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings.

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