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Net Investment Gains (Losses) (Change in Unrealized Gains (Losses) of Available For Sales Securities) (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
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Jun. 30, 2022 | Jun. 30, 2021 | Jun. 30, 2022 | Jun. 30, 2021
Realized and Unrealized Investment Gains Losses [Line Items] |  |  |  |
Total change in unrealized investment (losses) gains | $ (430,784) | $ 28,804 | $ (970,232) | $ (84,931)
Income tax benefit (expense) | 93,776 | (5,532) | 209,679 | 18,073
Noncontrolling interests | 0 | (1) | (1) | (1)
Total change in unrealized gains | (337,008) | 23,271 | (760,554) | (66,859)
Debt securities |  |  |  |
Realized and Unrealized Investment Gains Losses [Line Items] |  |  |  |
Total change in unrealized investment (losses) gains | (409,647) | 28,511 | (949,910) | (94,058)
Fixed maturity securities with allowance for expected credit losses |  |  |  |
Realized and Unrealized Investment Gains Losses [Line Items] |  |  |  |
Total change in unrealized investment (losses) gains | (16,878) | (69) | (16,585) | 10,286
Investment funds |  |  |  |
Realized and Unrealized Investment Gains Losses [Line Items] |  |  |  |
Total change in unrealized investment (losses) gains | (3,302) | 762 | (2,833) | (257)
Other |  |  |  |
Realized and Unrealized Investment Gains Losses [Line Items] |  |  |  |
Total change in unrealized investment (losses) gains | $ (957) | $ (400) | $ (904) | $ (902)

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