Short-Duration Insurance Contracts - Schedule of Net Incurred and Paid Claims (Details) - USD ($) $ in Millions |
Jun. 30, 2025 |
Mar. 31, 2025 |
Dec. 31, 2024 |
Jun. 30, 2024 |
Mar. 31, 2024 |
Dec. 31, 2023 |
|---|---|---|---|---|---|---|
| Short-Duration Insurance Contracts, Historical Claims Duration [Line Items] | ||||||
| Unpaid claims and claim expenses | $ 576.6 | $ 569.2 | ||||
| Total short-duration insurance contracts | ||||||
| Short-Duration Insurance Contracts, Historical Claims Duration [Line Items] | ||||||
| Unpaid claims and claim expenses | 533.0 | 525.5 | ||||
| Property & Casualty | ||||||
| Short-Duration Insurance Contracts, Historical Claims Duration [Line Items] | ||||||
| Unpaid claims and claim expenses | 419.8 | 420.6 | ||||
| Group Benefits | ||||||
| Short-Duration Insurance Contracts, Historical Claims Duration [Line Items] | ||||||
| Unpaid claims and claim expenses | 113.2 | $ 109.0 | 104.9 | $ 116.1 | $ 114.3 | $ 116.6 |
| Other than short-duration | ||||||
| Short-Duration Insurance Contracts, Historical Claims Duration [Line Items] | ||||||
| Unpaid claims and claim expenses | $ 43.6 | $ 43.7 |