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v3.25.3

Fair Value OF Financial Instrument - Quantitative Information about Significant Unobservable Inputs for Level 3 Recurring Fair Value Measurements (Details) $ in Millions | Sep. 30, 2025 USD ($) | Jun. 30, 2025 USD ($) | Dec. 31, 2024 USD ($) | Sep. 30, 2024 USD ($) | Jun. 30, 2024 USD ($) | Dec. 31, 2023 USD ($)
--- | --- | --- | --- | --- | --- | ---
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |  |  |  |  |
Fair Value | $ 5,666.5 |  | $ 5,387.9 |  |  |
Net MRBs | (9.3) | $ (6.7) | (6.8) | $ (5.7) | $ (6.2) | $ (3.9)
Corporate bonds |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |  |  |  |  |
Fair Value | 1,840.7 |  | 1,782.4 |  |  |
Fair Value | Fair Value, Recurring |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |  |  |  |  |
Fair Value | 5,666.5 |  | 5,387.9 |  |  |
Fair Value | Fair Value, Recurring | Corporate bonds |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |  |  |  |  |
Fair Value | $ 1,840.8 |  | 1,782.4 |  |  |
Level 3 | Minimum | option budget | discounted cash flow |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |  |  |  |  |
Derivatives embedded in fixed indexed annuity products, measurement input | 0.009 |  |  |  |  |
Level 3 | Maximum | option budget | discounted cash flow |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |  |  |  |  |
Derivatives embedded in fixed indexed annuity products, measurement input | 0.038 |  |  |  |  |
Level 3 | Weighted Average | lapse rate | discounted cash flow |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |  |  |  |  |
Derivatives embedded in fixed indexed annuity products, measurement input | 0.075 |  |  |  |  |
Net MRBs, measurement input | 0.075 |  |  |  |  |
Level 3 | Weighted Average | mortality multiplier | discounted cash flow |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |  |  |  |  |
Derivatives embedded in fixed indexed annuity products, measurement input | 0.710 |  |  |  |  |
Net MRBs, measurement input | 0.710 |  |  |  |  |
Level 3 | Weighted Average | non-performance adjustment | discounted cash flow |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |  |  |  |  |
Derivatives embedded in fixed indexed annuity products, measurement input | 0.050 |  |  |  |  |
Level 3 | Corporate bonds | Minimum | yield | discounted cash flow | Internal |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |  |  |  |  |
Corporate bonds, measurement input | 0.032 |  |  |  |  |
Level 3 | Corporate bonds | Minimum | option adjusted spread | discounted cash flow |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |  |  |  |  |
Corporate bonds, measurement input | 0.0255 |  |  |  |  |
Level 3 | Corporate bonds | Maximum | yield | discounted cash flow | Internal |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |  |  |  |  |
Corporate bonds, measurement input | 0.088 |  |  |  |  |
Level 3 | Corporate bonds | Maximum | option adjusted spread | discounted cash flow |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |  |  |  |  |
Corporate bonds, measurement input | 0.0781 |  |  |  |  |
Level 3 | Fair Value | Fair Value, Recurring |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |  |  |  |  |
Fair Value | $ 477.4 |  | 499.9 |  |  |
Derivatives embedded in fixed indexed annuity products | 79.1 |  |  |  |  |
Net MRBs | (9.3) |  |  |  |  |
Level 3 | Fair Value | Fair Value, Recurring | Internal |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |  |  |  |  |
Fair Value | 193.6 |  | 199.3 |  |  |
Level 3 | Fair Value | Fair Value, Recurring | Corporate bonds |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |  |  |  |  |
Fair Value | 340.2 |  | 351.3 |  |  |
Level 3 | Fair Value | Fair Value, Recurring | Corporate bonds | Internal |  |  |  |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Line Items] |  |  |  |  |  |
Fair Value | $ 193.6 |  | $ 199.3 |  |  |

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