Net Finance Income or Expense from Insurance Contracts and Reinsurance Contract Assets Held - Changes in discount rates (Details) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Net Finance Income or Expense from Insurance Contracts and Reinsurance Contract Assets Held | ||
| Effect of changes in discount rates on total bonds (recognized in net gains on investments) | $ 385.4 | $ (731.3) |
| Effect of changes in discount rates on insurance contracts and reinsurance contract assets held (recognized in net finance income (expense) from insurance contracts and reinsurance contract assets held) | (443.9) | 201.4 |
| Net benefit (loss) from changes in discount rates in consolidated statement of earnings | $ (58.5) | $ (529.9) |