Note 2 - Securities (Tables)
|
6 Months Ended |
Jun. 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 | |
| June 30, 2026 | | | | | | | | | | | | | | | | |
| U.S. Treasury notes and bonds | | $ | 55,805 | | | $ | 0 | | | $ | (706 | ) | | $ | 55,099 | |
| U.S. Government agency debt obligations | | | 716,342 | | | | 1,008 | | | | (29,842 | ) | | | 687,508 | |
| Mortgage-backed securities | | | 75,258 | | | | 7 | | | | (6,066 | ) | | | 69,199 | |
| Municipal general obligation bonds | | | 213,901 | | | | 1,804 | | | | (4,532 | ) | | | 211,173 | |
| Municipal revenue bonds | | | 65,546 | | | | 176 | | | | (2,094 | ) | | | 63,628 | |
| Other investments | | | 39,185 | | | | 0 | | | | (263 | ) | | | 38,922 | |
| | | | | | | | | | | | | | | | | |
| | | $ | 1,166,037 | | | $ | 2,995 | | | $ | (43,503 | ) | | $ | 1,125,529 | |
| | | | | | | | | | | | | | | | | |
| 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 | |
| June 30, 2026 | | | | | | | | | | | | | | | | | | | | | | | | |
| U.S. Treasury notes and bonds | | $ | 55,099 | | | $ | 706 | | | $ | 0 | | | $ | 0 | | | $ | 55,099 | | | $ | 706 | |
| U.S. Government agency debt obligations | | | 177,740 | | | | 2,269 | | | | 394,004 | | | | 27,573 | | | | 571,744 | | | | 29,842 | |
| Mortgage-backed securities | | | 46,699 | | | | 1,170 | | | | 21,768 | | | | 4,896 | | | | 68,467 | | | | 6,066 | |
| Municipal general obligation bonds | | | 13,879 | | | | 185 | | | | 99,531 | | | | 4,347 | | | | 113,410 | | | | 4,532 | |
| Municipal revenue bonds | | | 31,407 | | | | 411 | | | | 22,332 | | | | 1,683 | | | | 53,739 | | | | 2,094 | |
| Other investments | | | 37,424 | | | | 263 | | | | 0 | | | | 0 | | | | 37,424 | | | | 263 | |
| | | | | | | | | | | | | | | | | | | | | | | | | |
| | | $ | 362,248 | | | $ | 5,004 | | | $ | 537,635 | | | $ | 38,499 | | | $ | 899,883 | | | $ | 43,503 | |
| | | | | | | | | | | | | | | | | | | | | | | | | |
| 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 | | $ | 52,714 | | | $ | 52,448 | |
| Due in 2027 through 2031 | | | 686,248 | | | | 662,249 | |
| Due in 2032 through 2036 | | | 241,078 | | | | 230,245 | |
| Due in 2037 and beyond | | | 71,554 | | | | 72,466 | |
| Mortgage-backed securities | | | 75,258 | | | | 69,199 | |
| Other investments | | | 39,185 | | | | 38,922 | |
| | | | | | | | | |
| | | $ | 1,166,037 | | | $ | 1,125,529 | |
|