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Investments (Realized and Unrealized Gains (Losses) on Equity Securities) (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022
Gain (Loss) on Securities [Line Items] |  |  |  |
Unrealized gains (losses) recognized in income on equity securities remaining in our portfolio at end of period | $ 200 | $ (5,832) | $ 2,744 | $ (16,334)
Unrealized gains (losses) recognized in income on equity securities sold in period | 289 | (1,945) | 5,918 | (15,457)
Total unrealized gains (losses) recognized in income on equity securities | $ 489 | $ (7,777) | $ 8,662 | $ (31,791)

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