| Comprehensive Income (Loss) Note [Text Block] |
Other Comprehensive Income (Loss):
The following tables represent the changes in accumulated other comprehensive income (loss) by component, net of tax, for the three and six month periods ended June 30, 2026 and 2025.
| | | | | | | Reclassification | | | | | | | | | |
| | | Net unrealized | | | adjustment for | | | | | | | | | |
| | | holding (losses) | | | (gains) losses | | | | | | | | | |
| | | gains on available | | | realized in income | | | Change in funded status | | | | | |
| (In Thousands of Dollars) | | for sale securities | | | on fair value hedge | | | of post-retirement plan | | | Total | |
| Balance December 31, 2025 | | $ | (143,597 | ) | | $ | (476 | ) | | $ | (2 | ) | | $ | (144,075 | ) |
| Other comprehensive (loss) before reclassification | | | (6,270 | ) | | | 0 | | | | 0 | | | | (6,270 | ) |
| Amounts reclassified from accumulated other comprehensive income | | | 0 | | | | 190 | | | | 0 | | | | 190 | |
| Net current period other comprehensive (loss) income | | | (6,270 | ) | | | 190 | | | | 0 | | | | (6,080 | ) |
| Balance March 31, 2026 | | $ | (149,867 | ) | | $ | (286 | ) | | $ | (2 | ) | | $ | (150,155 | ) |
| Other comprehensive income before reclassification | | | 3,264 | | | | 0 | | | | 0 | | | | 3,264 | |
| Amounts reclassified from accumulated other comprehensive income | | | 0 | | | | 202 | | | | 0 | | | | 202 | |
| Net current period other comprehensive income | | | 3,264 | | | | 202 | | | | 0 | | | | 3,466 | |
| Balance June 30, 2026 | | $ | (146,603 | ) | | $ | (84 | ) | | $ | (2 | ) | | $ | (146,689 | ) |
| | | | | | | | | | | | | | | | | |
| Balance December 31, 2024 | | $ | (192,860 | ) | | $ | (403 | ) | | $ | (2 | ) | | $ | (193,265 | ) |
| Other comprehensive income before reclassification | | | 15,096 | | | | 0 | | | | 0 | | | | 15,096 | |
| Amounts reclassified from accumulated other comprehensive income (loss) | | | 1,054 | | | | (186 | ) | | | 0 | | | | 868 | |
| Net current period other comprehensive income (loss) | | | 16,150 | | | | (186 | ) | | | 0 | | | | 15,964 | |
| Balance March 31, 2025 | | $ | (176,710 | ) | | $ | (589 | ) | | $ | (2 | ) | | $ | (177,301 | ) |
| Other comprehensive loss before reclassification | | | 517 | | | | 0 | | | | 0 | | | | 517 | |
| Amounts reclassified from accumulated other comprehensive income | | | 0 | | | | 46 | | | | 0 | | | | 46 | |
| Net current period other comprehensive (loss) income | | | 517 | | | | 46 | | | | 0 | | | | 563 | |
| Balance June 30, 2025 | | $ | (176,193 | ) | | $ | (543 | ) | | $ | (2 | ) | | $ | (176,738 | ) |
Amounts reclassified out of each component of accumulated other comprehensive income (loss) were not material for the three and six month periods ended June 30, 2026 and 2025.
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