| Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] |
| | | Three Months Ended June 30, | | | Six Months Ended June 30, | |
| (In thousands, except per share amounts) | | 2026 | | | 2025 | | | 2026 | | | 2025 | |
| Net income | | $ | 7,647 | | | $ | 5,797 | | | $ | 16,668 | | | $ | 11,233 | |
| Total weighted average shares outstanding - basic | | | 10,607,949 | | | | 7,534,264 | | | | 10,604,445 | | | | 7,511,285 | |
| Basic earnings per common share | | $ | 0.72 | | | $ | 0.77 | | | $ | 1.57 | | | $ | 1.50 | |
| | | | | | | | | | | | | | | | | |
| Net income | | $ | 7,647 | | | $ | 5,797 | | | $ | 16,668 | | | $ | 11,233 | |
| Total weighted average shares outstanding - basic | | | 10,607,949 | | | | 7,534,264 | | | | 10,604,445 | | | | 7,511,285 | |
| Add: dilutive impact of restricted stock | | | 168,975 | | | | 152,121 | | | | 170,621 | | | | 173,691 | |
| Total weighted average shares outstanding - diluted | | | 10,776,924 | | | | 7,686,385 | | | | 10,775,066 | | | | 7,684,976 | |
| Diluted earnings per common share | | $ | 0.71 | | | $ | 0.75 | | | $ | 1.55 | | | $ | 1.46 | |
| Anti-dilutive awards (1) | | | - | | | | - | | | | - | | | | 3 | |
|
| Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block] |
| | | June 30, 2026 | | | December 31, 2025 | |
| | | | | | | | | | | | | | | | | |
| (In thousands) | | Amount | | | Ratio | | | Amount | | | Ratio | |
| Leverage Ratio | | | | | | | | | | | | | | | | |
| Avidbank Holdings, Inc. | | $ | 294,950 | | | | 11.50 | % | | $ | 275,669 | | | | 11.23 | % |
| Minimum regulatory requirement | | $ | 102,555 | | | | 4.00 | % | | $ | 98,167 | | | | 4.00 | % |
| | | | | | | | | | | | | | | | | |
| Avidbank | | $ | 306,604 | | | | 11.99 | % | | $ | 285,091 | | | | 11.65 | % |
| Minimum requirement for "Well-Capitalized" institution | | $ | 127,820 | | | | 5.00 | % | | $ | 122,359 | | | | 5.00 | % |
| Minimum regulatory requirement | | $ | 102,256 | | | | 4.00 | % | | $ | 97,887 | | | | 4.00 | % |
| | | | | | | | | | | | | | | | | |
| Common Equity Tier I | | | | | | | | | | | | | | | | |
| Avidbank Holdings, Inc. | | $ | 294,950 | | | | 11.35 | % | | $ | 275,669 | | | | 11.05 | % |
| Minimum regulatory requirement | | $ | 116,939 | | | | 4.50 | % | | $ | 112,249 | | | | 4.50 | % |
| | | | | | | | | | | | | | | | | |
| Avidbank | | $ | 306,604 | | | | 11.83 | % | | $ | 285,091 | | | | 11.46 | % |
| Minimum requirement for "Well-Capitalized" institution | | $ | 168,415 | | | | 6.50 | % | | $ | 161,678 | | | | 6.50 | % |
| Minimum regulatory requirement | | $ | 116,595 | | | | 4.50 | % | | $ | 111,931 | | | | 4.50 | % |
| | | | | | | | | | | | | | | | | |
| Tier 1 Risk-Based Capital Ratio | | | | | | | | | | | | | | | | |
| Avidbank Holdings, Inc. | | $ | 294,950 | | | | 11.35 | % | | $ | 275,669 | | | | 11.05 | % |
| Minimum regulatory requirement | | $ | 155,918 | | | | 6.00 | % | | $ | 149,665 | | | | 6.00 | % |
| | | | | | | | | | | | | | | | | |
| Avidbank | | $ | 306,604 | | | | 11.83 | % | | $ | 285,091 | | | | 11.46 | % |
| Minimum requirement for "Well-Capitalized" institution | | $ | 207,280 | | | | 8.00 | % | | $ | 198,988 | | | | 8.00 | % |
| Minimum regulatory requirement | | $ | 155,460 | | | | 6.00 | % | | $ | 149,241 | | | | 6.00 | % |
| | | | | | | | | | | | | | | | | |
| Total Risk-Based Capital Ratio | | | | | | | | | | | | | | | | |
| Avidbank Holdings, Inc. | | $ | 332,342 | | | | 12.79 | % | | $ | 313,481 | | | | 12.57 | % |
| Minimum regulatory requirement | | $ | 207,891 | | | | 8.00 | % | | $ | 199,554 | | | | 8.00 | % |
| | | | | | | | | | | | | | | | | |
| Avidbank | | $ | 330,796 | | | | 12.77 | % | | $ | 309,703 | | | | 12.45 | % |
| Minimum requirement for "Well-Capitalized" institution | | $ | 259,100 | | | | 10.00 | % | | $ | 248,735 | | | | 10.00 | % |
| Minimum regulatory requirement | | $ | 207,280 | | | | 8.00 | % | | $ | 198,988 | | | | 8.00 | % |
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