| Debt Securities, Trading, and Equity Securities, FV-NI [Table Text Block] |
| June 30, 2023 |
|
Amortized
Cost |
|
|
Gross
Unrealized
Gains |
|
|
Gross
Unrealized
Losses |
|
|
Fair
Value |
|
| Available for Sale |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| U.S. Treasury and federal agency securities |
|
$ |
255,547 |
|
|
$ |
— |
|
|
$ |
(15,366 |
) |
|
$ |
240,181 |
|
| U.S. Agency MBS and CMOs |
|
|
130,977 |
|
|
|
— |
|
|
|
(14,828 |
) |
|
|
116,149 |
|
| Tax-exempt state and municipal bonds |
|
|
35,218 |
|
|
|
5 |
|
|
|
(612 |
) |
|
|
34,611 |
|
| Taxable state and municipal bonds |
|
|
117,976 |
|
|
|
36 |
|
|
|
(7,831 |
) |
|
|
110,181 |
|
| Corporate bonds and other debt securities |
|
|
12,136 |
|
|
|
— |
|
|
|
(421 |
) |
|
|
11,715 |
|
| |
|
$ |
551,854 |
|
|
$ |
41 |
|
|
$ |
(39,058 |
) |
|
$ |
512,837 |
|
| Held to Maturity |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| U.S. Treasury |
|
$ |
251,266 |
|
|
$ |
— |
|
|
$ |
(13,162 |
) |
|
$ |
238,104 |
|
| Tax-exempt state and municipal bonds |
|
|
89,134 |
|
|
|
199 |
|
|
|
(2,083 |
) |
|
|
87,250 |
|
| |
|
$ |
340,400 |
|
|
$ |
199 |
|
|
$ |
(15,245 |
) |
|
$ |
325,354 |
|
| December 31, 2022 |
|
Amortized
Cost |
|
|
Gross
Unrealized
Gains |
|
|
Gross
Unrealized
Losses |
|
|
Fair
Value |
|
| Available for Sale: |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| U.S. Treasury and federal agency securities |
|
$ |
240,921 |
|
|
$ |
23 |
|
|
$ |
(16,310 |
) |
|
$ |
224,634 |
|
| U.S. Agency MBS and CMOs |
|
|
128,165 |
|
|
|
— |
|
|
|
(14,347 |
) |
|
|
113,818 |
|
| Tax-exempt state and municipal bonds |
|
|
37,198 |
|
|
|
10 |
|
|
|
(498 |
) |
|
|
36,710 |
|
| Taxable state and municipal bonds |
|
|
120,647 |
|
|
|
49 |
|
|
|
(8,525 |
) |
|
|
112,171 |
|
| Corporate bonds and other debt securities |
|
|
12,387 |
|
|
|
— |
|
|
|
(463 |
) |
|
|
11,924 |
|
| |
|
$ |
539,318 |
|
|
$ |
82 |
|
|
$ |
(40,143 |
) |
|
$ |
499,257 |
|
| Held to Maturity |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| U.S. Treasury |
|
$ |
251,307 |
|
|
$ |
— |
|
|
$ |
(13,677 |
) |
|
$ |
237,630 |
|
| Tax-exempt state and municipal bonds |
|
|
97,458 |
|
|
|
415 |
|
|
|
(2,853 |
) |
|
|
95,020 |
|
| |
|
$ |
348,765 |
|
|
$ |
415 |
|
|
$ |
(16,530 |
) |
|
$ |
332,650 |
|
| |
|
Held–to-Maturity Securities |
|
|
Available-for-Sale Securities |
|
| |
|
Amortized
Cost |
|
|
Fair
Value |
|
|
Amortized
Cost |
|
|
Fair
Value |
|
| Due in one year or less |
|
$ |
115,991 |
|
|
$ |
113,729 |
|
|
$ |
60,850 |
|
|
$ |
59,717 |
|
| Due from one to five years |
|
|
206,975 |
|
|
|
194,472 |
|
|
|
336,794 |
|
|
|
316,350 |
|
| Due from five to ten years |
|
|
17,434 |
|
|
|
17,153 |
|
|
|
24,734 |
|
|
|
22,027 |
|
| Due after ten years |
|
|
— |
|
|
|
— |
|
|
|
129,476 |
|
|
|
114,743 |
|
| |
|
$ |
340,400 |
|
|
$ |
325,354 |
|
|
$ |
551,854 |
|
|
$ |
512,837 |
|
|
| Schedule of Unrealized Loss on Investments [Table Text Block] |
| |
|
Less than 12 Months |
|
|
12 Months or More |
|
|
Total |
|
| June 30, 2023 |
|
Fair
Value |
|
|
Unrealized
Loss |
|
|
Fair
Value |
|
|
Unrealized
Loss |
|
|
Fair
Value |
|
|
Unrealized
Loss |
|
| Available for Sale |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| U.S. Treasury and federal agency securities |
|
$ |
53,921 |
|
|
$ |
(1,053 |
) |
|
$ |
182,058 |
|
|
$ |
(14,313 |
) |
|
$ |
235,979 |
|
|
$ |
(15,366 |
) |
| U.S. Agency MBS and CMOs |
|
|
50,238 |
|
|
|
(1,450 |
) |
|
|
65,911 |
|
|
|
(13,378 |
) |
|
|
116,149 |
|
|
|
(14,828 |
) |
| Tax-exempt state and municipal bonds |
|
|
30,453 |
|
|
|
(369 |
) |
|
|
5,451 |
|
|
|
(243 |
) |
|
|
35,904 |
|
|
|
(612 |
) |
| Taxable state and municipal bonds |
|
|
31,301 |
|
|
|
(833 |
) |
|
|
73,536 |
|
|
|
(6,998 |
) |
|
|
104,837 |
|
|
|
(7,831 |
) |
| Corporate bonds and other debt securities |
|
|
5,445 |
|
|
|
(161 |
) |
|
|
6,270 |
|
|
|
(260 |
) |
|
|
11,715 |
|
|
|
(421 |
) |
| |
|
$ |
171,358 |
|
|
$ |
(3,866 |
) |
|
$ |
333,226 |
|
|
$ |
(35,192 |
) |
|
$ |
504,584 |
|
|
$ |
(39,058 |
) |
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Held to Maturity |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| U.S. Treasury |
|
$ |
29,018 |
|
|
$ |
(566 |
) |
|
$ |
209,086 |
|
|
$ |
(12,596 |
) |
|
$ |
238,104 |
|
|
$ |
(13,162 |
) |
| Tax-exempt state and municipal bonds |
|
|
10,527 |
|
|
|
(88 |
) |
|
|
47,479 |
|
|
|
(1,995 |
) |
|
|
58,006 |
|
|
|
(2,083 |
) |
| |
|
$ |
39,545 |
|
|
$ |
(654 |
) |
|
$ |
256,565 |
|
|
$ |
(14,591 |
) |
|
$ |
296,110 |
|
|
$ |
(15,245 |
) |
| |
|
Less than 12 Months |
|
|
12 Months or More |
|
|
Total |
|
| December 31, 2022 |
|
Fair
Value |
|
|
Unrealized
Loss |
|
|
Fair
Value |
|
|
Unrealized
Loss |
|
|
Fair
Value |
|
|
Unrealized
Loss |
|
| Available for Sale: |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| U.S. Treasury and federal agency securities |
|
$ |
144,796 |
|
|
$ |
(6,230 |
) |
|
$ |
66,008 |
|
|
$ |
(10,080 |
) |
|
$ |
210,804 |
|
|
$ |
(16,310 |
) |
| U.S. Agency MBS and CMOs |
|
|
64,427 |
|
|
|
(4,789 |
) |
|
|
41,340 |
|
|
|
(9,558 |
) |
|
|
105,767 |
|
|
|
(14,347 |
) |
| Tax-exempt state and municipal bonds |
|
|
31,337 |
|
|
|
(498 |
) |
|
|
— |
|
|
|
— |
|
|
|
31,337 |
|
|
|
(498 |
) |
| Taxable state and municipal bonds |
|
|
71,165 |
|
|
|
(3,337 |
) |
|
|
33,452 |
|
|
|
(5,188 |
) |
|
|
104,617 |
|
|
|
(8,525 |
) |
| Corporate bonds and other debt securities |
|
|
10,668 |
|
|
|
(357 |
) |
|
|
1,256 |
|
|
|
(106 |
) |
|
|
11,924 |
|
|
|
(463 |
) |
| |
|
$ |
322,393 |
|
|
$ |
(15,211 |
) |
|
$ |
142,056 |
|
|
$ |
(24,932 |
) |
|
$ |
464,449 |
|
|
$ |
(40,143 |
) |
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Held to Maturity: |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| U.S. Treasury |
|
$ |
237,630 |
|
|
$ |
(13,677 |
) |
|
$ |
— |
|
|
$ |
— |
|
|
$ |
237,630 |
|
|
$ |
(13,677 |
) |
| Tax-exempt state and municipal bonds |
|
|
57,671 |
|
|
|
(2,314 |
) |
|
|
21,721 |
|
|
|
(539 |
) |
|
|
79,392 |
|
|
|
(2,853 |
) |
| |
|
$ |
295,301 |
|
|
$ |
(15,991 |
) |
|
$ |
21,721 |
|
|
$ |
(539 |
) |
|
$ |
317,022 |
|
|
$ |
(16,530 |
) |
|