Consolidated Statements of Comprehensive Income - USD ($) |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
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| Statement of Comprehensive Income [Abstract] | ||||
| Net income | $ 113,773,000 | $ 91,365,000 | $ 224,860,000 | $ 186,163,000 |
| Reclassification adjustment for net losses on AFS securities included in net income, net of tax | 5,937,000 | 0 | 5,937,000 | 0 |
| Unrealized (losses) gains, net of tax | (17,838,000) | 21,350,000 | (56,036,000) | 66,993,000 |
| Change in pension surplus, net of tax | 419,000 | 5,219,000 | 1,438,000 | 8,636,000 |
| Total other comprehensive (loss) income | (11,482,000) | 26,569,000 | (48,661,000) | 75,629,000 |
| Total comprehensive income | $ 102,291,000 | $ 117,934,000 | $ 176,199,000 | $ 261,792,000 |
| X | ||||||||||
- Definition Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount after tax of other comprehensive income (loss) attributable to parent entity. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount, after tax and reclassification adjustment, of (increase) decrease in accumulated other comprehensive income for defined benefit plan. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Amount after tax of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Amount, after tax and before adjustment, of unrealized holding gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Excludes unrealized gain (loss) on investment in debt security measured at amortized cost (held-to-maturity) from transfer to available-for-sale. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- References No definition available.
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