Short-Duration Insurance Contracts - Schedule of Net Incurred and Paid Claims (Details) - USD ($) $ in Millions |
Sep. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Short-Duration Insurance Contracts, Historical Claims Duration [Line Items] | ||
| Unpaid claims and claim expenses | $ 571.3 | $ 565.2 |
| Total short-duration insurance contracts | ||
| Short-Duration Insurance Contracts, Historical Claims Duration [Line Items] | ||
| Unpaid claims and claim expenses | 519.7 | 517.7 |
| Property & Casualty | ||
| Short-Duration Insurance Contracts, Historical Claims Duration [Line Items] | ||
| Unpaid claims and claim expenses | 406.1 | 404.5 |
| Group Benefits | ||
| Short-Duration Insurance Contracts, Historical Claims Duration [Line Items] | ||
| Unpaid claims and claim expenses | 113.6 | 113.2 |
| Other than short-duration | ||
| Short-Duration Insurance Contracts, Historical Claims Duration [Line Items] | ||
| Unpaid claims and claim expenses | $ 51.6 | $ 47.5 |