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Marketable Securities (Narrative) (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
Schedule of Investments [Line Items] |  |  |
Cash equivalents fair value | $ 450,240 | $ 422,838 |
Net unrealized holding gain (loss) | (9,294) | (62) |
Net unrealized holding gains (losses), income tax expense (benefit) | (2,777) | (18) |
Equity securities, gross realized gains | 263 | 741 | $ 1,100
Equity securities, gross realized losses | 773 | 72 | 250
Investment funds sponsored by LSV | 104,673 | 107,918 |
Securities owned | 32,148 | 28,267 |
Available for sale debt securities |  |  |
Schedule of Investments [Line Items] |  |  |
Available-for-sale securities, gross realized losses | 602 | 1,160 | 902
Available-for-sale securities, gross realized gains | 0 | 0 | 0
Investment funds sponsored by LSV |  |  |
Schedule of Investments [Line Items] |  |  |
Investment funds sponsored by LSV | 6,366 | 6,916 |
Gains (losses) from the change in fair value of the funds | $ (550) | $ 750 | $ 178

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- Definition Amount, after tax, of accumulated unrealized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14 -URI https://asc.fasb.org/extlink&oid=126968391&loc=d3e681-108580 + Details
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