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Investment In Unconsolidated Affiliate (Statement of Operations) (Details) - LSV Asset Management - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017
Schedule of Equity Method Investments [Line Items] |  |  |  |
Revenues | $ 133,921 | $ 126,723 | $ 397,750 | $ 355,996
Net income | $ 107,284 | $ 101,130 | $ 317,295 | $ 280,717

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