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Net Investment (Losses) Gains (Net Investment Gains (Losses)) (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
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Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024
Investments, Debt and Equity Securities [Abstract] |  |  |  |
Fixed maturity securities, gains | $ 6,930 | $ 4,799 | $ 13,771 | $ 11,448
Fixed maturity securities, losses | (6,088) | (3,884) | (14,454) | (11,569)
Net realized gains on investment sales | 53,920 | 407 | 50,225 | 102,205
Change in unrealized gains (losses) | 9,590 | (1,537) | 93,167 | (42,442)
Investment funds | (1,348) | (101) | (526) | 1,109
Real estate | 20,443 | 1,470 | 19,130 | (2,704)
Other (2) | (4,647) | (24,516) | (36,269) | (130,212)
Net realized and unrealized gains (losses) on investments in earnings before allowance for expected credit losses | 78,800 | (23,362) | 125,044 | (72,165)
Fixed maturity securities | 49 | 14,888 | 388 | 29,768
Loans receivable | 111 | 388 | 856 | 1,579
Change in allowance for expected credit losses on investments | 160 | 15,276 | 1,244 | 31,347
Net investment gains (losses) | 78,960 | (8,086) | 126,288 | (40,818)
Income tax (expense) benefit | (16,973) | 43 | (27,186) | 5,810
After-tax net investment gains (losses) | $ 61,987 | $ (8,043) | $ 99,102 | $ (35,008)

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