| Debt Securities, Available-for-Sale [Table Text Block] |
| June 30, 2026 | | U.S. Treasury notes | | | U.S. government agency obligations | | | Municipal obligations | | | Mortgage-backed residential obligations | | | Collateralized mortgage obligations | | | Total available-for-sale | |
| | | (Dollars in thousands) | |
| 1 year or less | | $ | 1,001 | | | $ | — | | | $ | 119 | | | $ | — | | | $ | 5,728 | | | $ | 6,848 | |
| 1 to 5 years | | | 6,019 | | | | 7,785 | | | | 1,206 | | | | 8,006 | | | | 13,355 | | | | 36,371 | |
| 5 to 10 years | | | — | | | | 368 | | | | 4,622 | | | | 13,192 | | | | 4,590 | | | | 22,772 | |
| After 10 years | | | — | | | | — | | | | 6,081 | | | | 553 | | | | 2,002 | | | | 8,636 | |
| Fair value | | | 7,020 | | | | 8,153 | | | | 12,028 | | | | 21,751 | | | | 25,675 | | | | 74,627 | |
| Gross unrealized gains | | | — | | | | — | | | | — | | | | — | | | | — | | | | — | |
| Gross unrealized losses | | | (87 | ) | | | (718 | ) | | | (1,842 | ) | | | (3,099 | ) | | | (2,620 | ) | | | (8,366 | ) |
| Amortized cost | | $ | 7,107 | | | $ | 8,871 | | | $ | 13,870 | | | $ | 24,850 | | | $ | 28,295 | | | $ | 82,993 | |
| December 31, 2025 | | U.S. Treasury notes | | | U.S. government agency obligations | | | Municipal obligations | | | Mortgage-backed residential obligations | | | Collateralized mortgage obligations | | | Total available-for-sale | |
| | | (Dollars in thousands) | |
| 1 year or less | | $ | — | | | $ | — | | | $ | 198 | | | $ | — | | | $ | 1,412 | | | $ | 1,610 | |
| 1 to 5 years | | | 7,085 | | | | 7,208 | | | | 1,202 | | | | 8,860 | | | | 17,757 | | | | 42,112 | |
| 5 to 10 years | | | — | | | | 1,326 | | | | 3,642 | | | | 14,336 | | | | 5,918 | | | | 25,222 | |
| After 10 years | | | — | | | | — | | | | 7,104 | | | | 573 | | | | 2,098 | | | | 9,775 | |
| Fair value | | $ | 7,085 | | | $ | 8,534 | | | $ | 12,146 | | | $ | 23,769 | | | $ | 27,185 | | | $ | 78,719 | |
| Gross unrealized gains | | | 4 | | | | — | | | | — | | | | — | | | | 1 | | | | 5 | |
| Gross unrealized losses | | | (7 | ) | | | (685 | ) | | | (1,829 | ) | | | (2,990 | ) | | | (2,552 | ) | | | (8,063 | ) |
| Amortized cost | | $ | 7,088 | | | $ | 9,219 | | | $ | 13,975 | | | $ | 26,759 | | | $ | 29,736 | | | $ | 86,777 | |
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| Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block] |
| | | Less than 12 Months | | | 12 Months or Longer | | | Total | |
| | | (Dollars in thousands) | |
| | | Fair | | | Unrealized | | | Fair | | | Unrealized | | | Fair | | | Unrealized | |
| | | Value | | | Losses | | | Value | | | Losses | | | Value | | | Losses | |
| June 30, 2026 | | | | | | | | | | | | | | | | | | | | | | | | |
| U.S. Treasury notes | | $ | 7,020 | | | $ | 87 | | | $ | — | | | $ | — | | | $ | 7,020 | | | $ | 87 | |
| U.S. government agency obligations | | | 986 | | | | 14 | | | | 7,167 | | | | 704 | | | | 8,153 | | | | 718 | |
| Municipal obligations | | | — | | | | — | | | | 12,028 | | | | 1,842 | | | | 12,028 | | | | 1,842 | |
| Mortgage-backed residential obligations | | | — | | | | — | | | | 21,751 | | | | 3,099 | | | | 21,751 | | | | 3,099 | |
| Collateralized mortgage obligations | | | 2,465 | | | | 49 | | | | 23,210 | | | | 2,571 | | | | 25,675 | | | | 2,620 | |
| Total | | $ | 10,471 | | | $ | 150 | | | $ | 64,156 | | | $ | 8,216 | | | $ | 74,627 | | | $ | 8,366 | |
| December 31, 2025 | | | | | | | | | | | | | | | | | | | | | | | | |
| U.S. Treasury notes | | $ | 2,990 | | | $ | 7 | | | $ | — | | | $ | — | | | $ | 2,990 | | | $ | 7 | |
| U.S. government agency obligations | | | 1,000 | | | | 1 | | | | 7,534 | | | | 684 | | | | 8,534 | | | | 685 | |
| Municipal obligations | | | — | | | | — | | | | 12,146 | | | | 1,829 | | | | 12,146 | | | | 1,829 | |
| Mortgage-backed residential obligations | | | — | | | | — | | | | 23,769 | | | | 2,990 | | | | 23,769 | | | | 2,990 | |
| Collateralized mortgage obligations | | | 1,530 | | | | 24 | | | | 24,654 | | | | 2,528 | | | | 26,184 | | | | 2,552 | |
| Total | | $ | 5,520 | | | $ | 32 | | | $ | 68,103 | | | $ | 8,031 | | | $ | 73,623 | | | $ | 8,063 | |
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