Restricted and Designated Cash and Investments - Schedule of Restricted and Designated Investments (Details) - USD ($) $ in Thousands |
Mar. 31, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Restricted Cash and Cash Equivalent Item [Line Items] | ||
| Restricted and designated investments | $ 60,107 | $ 61,362 |
| Funds held in trust for an asset retirement obligation by Bank of Montreal as trustee for SVPL | ||
| Restricted Cash and Cash Equivalent Item [Line Items] | ||
| Restricted and designated investments | 5,487 | 5,244 |
| Asset retirement obligations | ||
| Restricted Cash and Cash Equivalent Item [Line Items] | ||
| Restricted and designated investments | $ 54,620 | $ 56,118 |