Note 2 - Securities (Tables)
|
9 Months Ended |
Sep. 30, 2026 |
|---|
| Notes Tables |
|
| Debt Securities, Available-for-Sale [Table Text Block] |
| | | | | | | Gross | | | Gross | | | | | |
| | | Amortized | | | Unrealized | | | Unrealized | | | Fair | |
| (Dollars in thousands) | | Cost | | | Gains | | | Losses | | | Value | |
| September 30, 2026 | | | | | | | | | | | | | | | | |
| U.S. Treasury notes and bonds | | $ | 51,958 | | | $ | 0 | | | $ | (1,544 | ) | | $ | 50,414 | |
| U.S. Government agency debt obligations | | | 729,057 | | | | 1 | | | | (47,056 | ) | | | 682,002 | |
| Mortgage-backed securities | | | 79,706 | | | | 0 | | | | (10,994 | ) | | | 68,712 | |
| Municipal general obligation bonds | | | 213,234 | | | | 11 | | | | (14,235 | ) | | | 199,010 | |
| Municipal revenue bonds | | | 65,463 | | | | 10 | | | | (3,826 | ) | | | 61,647 | |
| Other investments | | | 36,782 | | | | 0 | | | | (551 | ) | | | 36,231 | |
| | | | | | | | | | | | | | | | | |
| | | $ | 1,176,200 | | | $ | 22 | | | $ | (78,206 | ) | | $ | 1,098,016 | |
| | | | | | | | | | | | | | | | | |
| December 31, 2025 | | | | | | | | | | | | | | | | |
| U.S. Treasury notes and bonds | | $ | 55,501 | | | $ | 0 | | | $ | 0 | | | $ | 55,501 | |
| U.S. Government agency debt obligations | | | 661,841 | | | | 4,343 | | | | (26,411 | ) | | | 639,773 | |
| Mortgage-backed securities | | | 80,475 | | | | 14 | | | | (4,727 | ) | | | 75,762 | |
| Municipal general obligation bonds | | | 217,283 | | | | 1,946 | | | | (4,166 | ) | | | 215,063 | |
| Municipal revenue bonds | | | 66,376 | | | | 180 | | | | (1,552 | ) | | | 65,004 | |
| Other investments | | | 51,127 | | | | 0 | | | | 0 | | | | 51,127 | |
| | | | | | | | | | | | | | | | | |
| | | $ | 1,132,603 | | | $ | 6,483 | | | $ | (36,856 | ) | | $ | 1,102,230 | |
|
| Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block] |
| | | Less than 12 Months | | | 12 Months or More | | | Total | |
| | | Fair | | | Unrealized | | | Fair | | | Unrealized | | | Fair | | | Unrealized | |
| (Dollars in thousands) | | Value | | | Loss | | | Value | | | Loss | | | Value | | | Loss | |
| September 30, 2026 | | | | | | | | | | | | | | | | | | | | | | | | |
| U.S. Treasury notes and bonds | | $ | 50,414 | | | $ | 1,544 | | | $ | 0 | | | $ | 0 | | | $ | 50,414 | | | $ | 1,544 | |
| U.S. Government agency debt obligations | | | 312,865 | | | | 11,603 | | | | 367,172 | | | | 35,453 | | | | 680,037 | | | | 47,056 | |
| Mortgage-backed securities | | | 48,899 | | | | 4,984 | | | | 19,720 | | | | 6,010 | | | | 68,619 | | | | 10,994 | |
| Municipal general obligation bonds | | | 87,913 | | | | 4,714 | | | | 101,275 | | | | 9,521 | | | | 189,188 | | | | 14,235 | |
| Municipal revenue bonds | | | 38,990 | | | | 1,214 | | | | 21,868 | | | | 2,612 | | | | 60,858 | | | | 3,826 | |
| Other investments | | | 35,729 | | | | 551 | | | | 0 | | | | 0 | | | | 35,729 | | | | 551 | |
| | | | | | | | | | | | | | | | | | | | | | | | | |
| | | $ | 574,810 | | | $ | 24,610 | | | $ | 510,035 | | | $ | 53,596 | | | $ | 1,084,845 | | | $ | 78,206 | |
| | | | | | | | | | | | | | | | | | | | | | | | | |
| December 31, 2025 | | | | | | | | | | | | | | | | | | | | | | | | |
| U.S. Treasury notes and bonds | | $ | 0 | | | $ | 0 | | | $ | 0 | | | $ | 0 | | | $ | 0 | | | $ | 0 | |
| U.S. Government agency debt obligations | | | 41,380 | | | | 234 | | | | 350,926 | | | | 26,177 | | | | 392,306 | | | | 26,411 | |
| Mortgage-backed securities | | | 0 | | | | 0 | | | | 22,945 | | | | 4,727 | | | | 22,945 | | | | 4,727 | |
| Municipal general obligation bonds | | | 4,465 | | | | 23 | | | | 102,736 | | | | 4,143 | | | | 107,201 | | | | 4,166 | |
| Municipal revenue bonds | | | 2,956 | | | | 13 | | | | 19,893 | | | | 1,539 | | | | 22,849 | | | | 1,552 | |
| Other investments | | | 0 | | | | 0 | | | | 0 | | | | 0 | | | | 0 | | | | 0 | |
| | | | | | | | | | | | | | | | | | | | | | | | | |
| | | $ | 48,801 | | | $ | 270 | | | $ | 496,500 | | | $ | 36,586 | | | $ | 545,301 | | | $ | 36,856 | |
|
| Investments Classified by Contractual Maturity Date [Table Text Block] |
| | | Amortized | | | Fair | |
| (Dollars in thousands) | | Cost | | | Value | |
| | | | | | | | | |
| Due in 2026 | | $ | 23,745 | | | $ | 23,689 | |
| Due in 2027 through 2031 | | | 708,067 | | | | 671,150 | |
| Due in 2032 through 2036 | | | 254,421 | | | | 230,674 | |
| Due in 2037 and beyond | | | 73,479 | | | | 67,560 | |
| Mortgage-backed securities | | | 79,706 | | | | 68,712 | |
| Other investments | | | 36,782 | | | | 36,231 | |
| | | | | | | | | |
| | | $ | 1,176,200 | | | $ | 1,098,016 | |
|