Related Party Transactions (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2017 |
|
| Subordinate voting shares | |||
| Related Party Transactions | |||
| Purchases for cancellation (in shares) | 1,006,535 | 1,346,953 | |
| Subordinate voting shares | Prem Watsa | |||
| Related Party Transactions | |||
| Purchases for cancellation (in shares) | 275,000 | ||
| Key Management Team | |||
| Related Party Transactions | |||
| Salaries and other short-term employee benefits | $ 15.0 | $ 17.3 | |
| Share-based payments | 7.5 | 7.2 | |
| Related party compensation | 22.5 | 24.5 | |
| Board of Directors | |||
| Related Party Transactions | |||
| Retainers and fees | 1.4 | 1.8 | |
| Share-based payments | 0.2 | 0.2 | |
| Related party compensation | $ 1.6 | 2.0 | |
| Non-insurance | Marval Guru Fund | |||
| Related Party Transactions | |||
| Investment in managed fund | $ 100.4 | $ 50.0 | |