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Investments - Net Realized and Unrealized Investment Gains and (Losses) (Details) - USD ($) $ in Thousands | 3 Months Ended
--- | ---
Mar. 31, 2024 | Mar. 31, 2023
Gain (Loss) on Securities [Line Items] |  |
Gross gains on sales | $ 2,135 | $ 3,784
Gross losses on sales | (1,965) | (12,930)
Net realized gains (losses) on disposals | 170 | (9,146)
Net unrealized gains (losses) on equity securities | 692 | 3,248
Losses on securities for which we have the intent to sell | (15) | (304)
Net realized and unrealized investment gains (losses) | (1,635) | 3,344
Available-for-Sale Securities |  |
Gain (Loss) on Securities [Line Items] |  |
Net credit loss benefit (expense) | (2,650) | 9,529
Commercial mortgage loans ("CMLs") |  |
Gain (Loss) on Securities [Line Items] |  |
Net credit loss benefit (expense) | $ 168 | $ 17

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