Capital structure - Regulatory Capital (Details) - USD ($) $ in Thousands |
Dec. 31, 2025 |
Dec. 31, 2024 |
|---|---|---|
| Capital | ||
| CET 1 capital | $ 1,102,302 | $ 1,066,058 |
| Tier 1 capital | 1,102,302 | 1,066,058 |
| Tier 2 capital | 6,189 | 107,061 |
| Total capital | 1,108,492 | 1,173,119 |
| Risk Weighted Assets | 3,991,389 | 4,539,376 |
| Leverage Ratio Exposure Measure | $ 14,520,704 | $ 14,679,662 |
| Capital Ratios (%) | ||
| Common Equity Tier 1, Actual | 27.60% | 23.50% |
| Common Equity Tier 1, Regulatory minimum | 10.00% | 10.00% |
| Total Tier 1, Actual | 0.276 | 0.235 |
| Total Tier 1, Regulatory minimum | 0.115 | 0.115 |
| Total Capital, Actual | 0.278 | 0.258 |
| Total Capital, Regulatory minimum | 0.135 | 0.135 |
| Leverage ratio, Actual | 0.076 | 0.073 |
| Leverage ratio, Regulatory minimum | 0.050 | 0.050 |
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- Definition Leverage Ratio Exposure Measure No definition available.
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- Definition Risk Based Ratios and Leverage Ratios [Abstract] [Abstract] No definition available.
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- Definition Tier One Common Equity No definition available.
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- Definition Tier One Common Equity Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets No definition available.
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- Definition Tier One Common Equity Risk Based Capital to Risk Weighted Assets No definition available.
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- Definition Tier One and Tier Two Risk Based Capital [Abstract] No definition available.
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- Definition Amount of total capital as defined by regulatory framework. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Ratio of minimum total risk-based capital to risk-weighted assets required for capital adequacy as defined by regulatory framework. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Ratio of total risk-based capital to risk-weighted assets as defined by regulatory framework. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of risk-weighted assets as defined by regulatory framework. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Ratio of minimum Tier 1 leverage capital to average assets required for capital adequacy as defined by regulatory framework. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Ratio of Tier 1 capital to average assets as defined by regulatory framework. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of Tier 1 risk-based capital as defined by regulatory framework. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Ratio of minimum Tier 1 risk-based capital to risk-weighted assets required for capital adequacy as defined by regulatory framework. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Ratio of Tier 1 risk-based capital to risk-weighted assets as defined by regulatory framework. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of Tier 2 risk-based capital as defined by regulatory framework. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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