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Investments Realized and Unrealized Gains (Losses) (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Gain (Loss) on Securities [Line Items] |  |  |
Gross gains on sales | $ 15,284 | $ 18,893 | $ 31,910
Gross losses on sales | (8,140) | (9,745) | (5,195)
Net realized investment gains (losses) on disposals | 7,144 | 9,148 | 26,715
Net unrealized losses on equity securities | 17,881 | 7,939 | (8,649)
Losses on securities for which we have the intent to sell | (519) | (16,266) |
OTTI Losses Gross |  |  | (3,644)
Net realized and unrealized investment gains (losses) | 17,599 | (4,217) | 14,422
Sale of equity securities | 99,235 | 1,320 | $ 137,294
Losses on securities for which we have the intent to sell | (519) | (16,266) |
Available-for-sale Securities [Member] |  |  |
Credit loss expense on investment portfolio | (6,858) | (5,042) |
Held-to-maturity Securities [Member] |  |  |
Credit loss expense on investment portfolio | $ (49) | $ 4 |

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