Derivatives and embedded derivatives - Schedule of notional amounts related to derivatives and embedded derivatives (Detail) - USD ($) $ in Thousands |
Jun. 30, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
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|---|---|---|---|---|---|
| Obligation to return digital asset collateral — embedded derivatives | |||||
| Embedded Derivative [Line Items] | |||||
| Derivative, notional amount | [1] | $ 0 | $ 1,905 | ||
| Investments – embedded derivatives | |||||
| Embedded Derivative [Line Items] | |||||
| Derivative, notional amount | $ 1,223 | 791 | 1,590 | ||
| Investments – derivatives | |||||
| Embedded Derivative [Line Items] | |||||
| Derivative, notional amount | $ 353 | $ 384 | $ 1,244 | ||
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