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Note D - Marketable Equity Securities - Unrealized Gains and Losses on Marketable Equity Securities (Details) - USD ($)
$ in Thousands
Sep. 30, 2021
Dec. 31, 2020
Gross unrealized gains $ 10,141 $ 7,048
Gross unrealized losses 3,596 4,967
Net unrealized gain $ 6,545 $ 2,081