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Investments (Net Realized and Unrealized Investment Gains and (Losses)) (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2023 | Jun. 30, 2022 | Jun. 30, 2023 | Jun. 30, 2022
Gain (Loss) on Securities [Line Items] |  |  |  |
Gross gains on sales | $ 1,156 | $ 14,552 | $ 4,940 | $ 16,749
Gross losses on sales | (11,952) | (19,345) | (24,882) | (32,905)
Net realized gains (losses) on disposals | (10,796) | (4,793) | (19,942) | (16,156)
Net unrealized gains (losses) on equity securities | 4,925 | (21,860) | 8,173 | (24,014)
Losses on securities for which we have the intent to sell | (341) | (702) | (645) | (5,499)
Net realized and unrealized investment gains (losses) | (5,426) | (42,880) | (2,082) | (83,232)
Available-for-sale Securities [Member] |  |  |  |
Gain (Loss) on Securities [Line Items] |  |  |  |
Net credit loss benefit (expense) on fixed income securities | 864 | (15,519) | 10,393 | (37,571)
Held-to-maturity Securities [Member] |  |  |  |
Gain (Loss) on Securities [Line Items] |  |  |  |
Net credit loss benefit (expense) on fixed income securities | 0 | (6) | 0 | 8
Commercial Mortgage Loans [Member] |  |  |  |
Gain (Loss) on Securities [Line Items] |  |  |  |
Net credit loss benefit (expense) on fixed income securities | $ (78) | $ 0 | $ (61) | $ 0

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