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v3.25.4

Investment Income and Gains and Losses (Narrative) (Details) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2025 | Dec. 31, 2024 | Dec. 31, 2023
Gain (Loss) on Investments [Line Items] |  |  |
Net unrealized gains (losses) recognized during the period on equity securities still held | $ 18.4 | $ 14.2 | $ 6.0
Fixed maturity securities on non-accrual | 0.0 | 0.0 | 14.8
Impairment losses on investment securities | 3.1 | 5.8 | 18.0
Impairments on fixed maturities credit related losses |  |  | 6.9
Allowance for credit losses | 8.1 | 5.7 | 10.0
Fixed Maturities [Member] |  |  |
Gain (Loss) on Investments [Line Items] |  |  |
Impairment losses on investment securities |  | 1.7 |
Fixed Maturities Intent to Sell Securities [Member] |  |  |
Gain (Loss) on Investments [Line Items] |  |  |
Impairment losses on investment securities |  |  | 11.1
Mortgage Loans on Real Estate [Member] |  |  |
Gain (Loss) on Investments [Line Items] |  |  |
Impairment losses on investment securities |  | 4.1 |
Allowance for credit losses | 8.1 | 5.7 |
Investments Net Asset Value [Member] |  |  |
Gain (Loss) on Investments [Line Items] |  |  |
Net unrealized gains (losses) recognized during the period on equity securities still held | $ (10.0) | $ (8.3) | $ (8.1)

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