| Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] |
| | | Fair Value Measurements Using | | | | | |
| | | Quoted Prices in Active Markets for Identical Assets (Level 1) | | | Significant Observable Inputs (Level 2) | | | Significant Unobservable Inputs (Level 3) | | | Fair Value | |
| September 30, 2025 | | | | | | | | | | | | | | | | |
| Securities: | | | | | | | | | | | | | | | | |
| Municipal securities | | $ | — | | | $ | 707 | | | $ | — | | | $ | 707 | |
| U.S. Treasury Bills and Notes | | | 533,354 | | | | — | | | | — | | | | 533,354 | |
| Mortgage-backed securities - residential | | | — | | | | 2,681 | | | | — | | | | 2,681 | |
| Collateralized mortgage obligations - residential | | | — | | | | 761 | | | | — | | | | 761 | |
| | | $ | 533,354 | | | $ | 4,149 | | | $ | — | | | $ | 537,503 | |
| December 31, 2024 | | | | | | | | | | | | | | | | |
| Securities: | | | | | | | | | | | | | | | | |
| Municipal securities | | $ | — | | | $ | 706 | | | $ | — | | | $ | 706 | |
| U.S. Treasury Bills and Notes | | | 246,290 | | | | — | | | | — | | | | 246,290 | |
| U.S. government-sponsored agencies | | | — | | | | 109,773 | | | | — | | | | 109,773 | |
| Mortgage-backed securities - residential | | | — | | | | 2,911 | | | | — | | | | 2,911 | |
| Collateralized mortgage obligations - residential | | | — | | | | 850 | | | | — | | | | 850 | |
| | | $ | 246,290 | | | $ | 114,240 | | | $ | — | | | $ | 360,530 | |
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| Fair Value, by Balance Sheet Grouping [Table Text Block] |
| | | | | | | Fair Value Measurements at September 30, 2025 Using: | | | | | |
| | | Carrying Amount | | | Level 1 | | | Level 2 | | | Level 3 | | | Total | |
| Financial assets | | | | | | | | | | | | | | | | | | | | |
| Cash and cash equivalents | | $ | 82,742 | | | $ | 82,270 | | | $ | 472 | | | $ | — | | | $ | 82,742 | |
| Interest-bearing time deposits in other financial institutions | | | 11,844 | | | | — | | | | 11,844 | | | | — | | | | 11,844 | |
| Securities | | | 537,503 | | | | 533,354 | | | | 4,149 | | | | — | | | | 537,503 | |
| Loans receivable, net of allowance for credit losses | | | 759,832 | | | | — | | | | — | | | | 728,297 | | | | 728,297 | |
| FHLB and FRB stock | | | 7,490 | | | | — | | | | — | | | | — | | | | N /A | |
| Accrued interest receivable | | | 4,514 | | | | 434 | | | | 144 | | | | 3,936 | | | | 4,514 | |
| Financial liabilities | | | | | | | | | | | | | | | | | | | | |
| Certificates of deposit | | | 261,860 | | | | — | | | | 261,003 | | | | — | | | | 261,003 | |
| Borrowings | | | 10,000 | | | | — | | | | 10,027 | | | | — | | | | 10,027 | |
| Subordinated notes | | | 18,274 | | | | — | | | | 17,390 | | | | — | | | | 17,390 | |
| | | | | | | Fair Value Measurements at December 31, 2024 Using: | | | | | |
| | | Carrying Amount | | | Level 1 | | | Level 2 | | | Level 3 | | | Total | |
| Financial assets | | | | | | | | | | | | | | | | | | | | |
| Cash and cash equivalents | | $ | 84,829 | | | $ | 84,399 | | | $ | 430 | | | $ | — | | | $ | 84,829 | |
| Interest-bearing time deposits in other financial institutions | | | 34,156 | | | | — | | | | 34,156 | | | | — | | | | 34,156 | |
| Securities | | | 360,530 | | | | 246,290 | | | | 114,240 | | | | — | | | | 360,530 | |
| Loans receivable, net of allowance for credit losses | | | 887,586 | | | | — | | | | — | | | | 845,303 | | | | 845,303 | |
| FHLB and FRB stock | | | 7,490 | | | | — | | | | — | | | | — | | | | N /A | |
| Accrued interest receivable | | | 6,401 | | | | 158 | | | | 1,452 | | | | 4,791 | | | | 6,401 | |
| Financial liabilities | | | | | | | | | | | | | | | | | | | | |
| Certificates of deposit | | | 234,979 | | | | — | | | | 233,639 | | | | — | | | | 233,639 | |
| Borrowings | | | 20,000 | | | | — | | | | 19,990 | | | | — | | | | 19,990 | |
| Subordinated notes | | | 18,736 | | | | — | | | | 17,571 | | | | — | | | | 17,571 | |
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