| Accumulated Other Comprehensive Income (Loss) [Table Text Block] |
A rollforward of the components of accumulated other comprehensive income (loss) is included as follows (in thousands): | | | | | | | | | | | | | | | | | | | | | | | | | | | Unrealized Gain (Loss) on | | | | | | | | | Available-for-Sale Securities | | Investment Securities Transferred from AFS | | | | | | Total | | Balance, Dec. 31, 2024 | | $ | (412,348) | | | $ | (90,692) | | | | | | | $ | (503,040) | | Net change in unrealized gain (loss) | | 260,657 | | | — | | | | | | | 260,657 | | | | | | | | | | | | | Reclassification adjustments included in earnings: | | | | | | | | | | | | Interest revenue, Investment securities | | — | | | 18,638 | | | | | | | 18,638 | | | | | | | | | | | | | | | | | | | | | | | | | Other comprehensive income (loss), before income taxes | | 260,657 | | | 18,638 | | | | | | | 279,295 | | | Federal and state income taxes | | 60,994 | | | 4,271 | | | | | | | 65,265 | | | Other comprehensive income (loss), net of income taxes | | 199,663 | | | 14,367 | | | | | | | 214,030 | | | Balance, June 30, 2025 | | $ | (212,685) | | | $ | (76,325) | | | | | | | $ | (289,010) | | | | | | | | | | | | | | Balance, Dec. 31, 2025 | | $ | (102,569) | | | $ | (63,601) | | | | | | | $ | (166,170) | | Net change in unrealized gain (loss) | | (128,537) | | | — | | | | | | | (128,537) | | | | | | | | | | | | | Reclassification adjustments included in earnings: | | | | | | | | | | | | Interest revenue, Investment securities | | — | | | 14,745 | | | | | | | 14,745 | | | | | | | | | | | | | | Loss on available-for-sale securities, net | | 4,645 | | | — | | | | | | | 4,645 | | | Other comprehensive income (loss), before income taxes | | (123,892) | | | 14,745 | | | | | | | (109,147) | | | Federal and state income taxes | | (29,277) | | | 3,485 | | | | | | | (25,792) | | | Other comprehensive income (loss), net of income taxes | | (94,615) | | | 11,260 | | | | | | | (83,355) | | | Balance, June 30, 2026 | | $ | (197,184) | | | $ | (52,341) | | | | | | | $ | (249,525) | |
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