| Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] |
| | | Three Months Ended March 31, | |
| (In thousands, except per share amounts) | | 2026 | | | 2025 | |
| Net income | | $ | 9,021 | | | $ | 5,436 | |
| Total weighted average shares outstanding - basic | | | 10,600,902 | | | | 7,488,051 | |
| Basic earnings per common share | | $ | 0.85 | | | $ | 0.73 | |
| | | | | | | | | |
| Net income | | $ | 9,021 | | | $ | 5,436 | |
| Total weighted average shares outstanding - basic | | | 10,600,902 | | | | 7,488,051 | |
| Add: dilutive impact of restricted stock | | | 172,982 | | | | 194,833 | |
| Total weighted average shares outstanding - diluted | | | 10,773,884 | | | | 7,682,884 | |
| Diluted earnings per common share | | $ | 0.84 | | | $ | 0.71 | |
| Anti-dilutive awards (1) | | | 508 | | | | 92 | |
|
| Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block] |
| | | March 31, 2026 | | | December 31, 2025 | |
| | | | | | | | | | | | | | | | | |
| (In thousands) | | Amount | | | Ratio | | | Amount | | | Ratio | |
| Leverage Ratio | | | | | | | | | | | | | | | | |
| Avidbank Holdings, Inc. | | $ | 284,814 | | | | 11.39 | % | | $ | 275,669 | | | | 11.23 | % |
| Minimum regulatory requirement | | $ | 99,985 | | | | 4.00 | % | | $ | 98,167 | | | | 4.00 | % |
| | | | | | | | | | | | | | | | | |
| Avidbank | | $ | 296,059 | | | | 11.88 | % | | $ | 285,091 | | | | 11.65 | % |
| Minimum requirement for "Well-Capitalized" institution | | $ | 124,622 | | | | 5.00 | % | | $ | 122,359 | | | | 5.00 | % |
| Minimum regulatory requirement | | $ | 99,698 | | | | 4.00 | % | | $ | 97,887 | | | | 4.00 | % |
| | | | | | | | | | | | | | | | | |
| Common Equity Tier I | | | | | | | | | | | | | | | | |
| Avidbank Holdings, Inc. | | $ | 284,814 | | | | 11.39 | % | | $ | 275,669 | | | | 11.05 | % |
| Minimum regulatory requirement | | $ | 112,564 | | | | 4.50 | % | | $ | 112,249 | | | | 4.50 | % |
| | | | | | | | | | | | | | | | | |
| Avidbank | | $ | 296,059 | | | | 11.87 | % | | $ | 285,091 | | | | 11.46 | % |
| Minimum requirement for "Well-Capitalized" institution | | $ | 162,114 | | | | 6.50 | % | | $ | 161,678 | | | | 6.50 | % |
| Minimum regulatory requirement | | $ | 112,233 | | | | 4.50 | % | | $ | 111,931 | | | | 4.50 | % |
| | | | | | | | | | | | | | | | | |
| Tier 1 Risk-Based Capital Ratio | | | | | | | | | | | | | | | | |
| Avidbank Holdings, Inc. | | $ | 284,814 | | | | 11.39 | % | | $ | 275,669 | | | | 11.05 | % |
| Minimum regulatory requirement | | $ | 150,085 | | | | 6.00 | % | | $ | 149,665 | | | | 6.00 | % |
| | | | | | | | | | | | | | | | | |
| Avidbank | | $ | 296,059 | | | | 11.87 | % | | $ | 285,091 | | | | 11.46 | % |
| Minimum requirement for "Well-Capitalized" institution | | $ | 199,525 | | | | 8.00 | % | | $ | 198,988 | | | | 8.00 | % |
| Minimum regulatory requirement | | $ | 149,644 | | | | 6.00 | % | | $ | 149,241 | | | | 6.00 | % |
| | | | | | | | | | | | | | | | | |
| Total Risk-Based Capital Ratio | | | | | | | | | | | | | | | | |
| Avidbank Holdings, Inc. | | $ | 321,315 | | | | 12.85 | % | | $ | 313,481 | | | | 12.57 | % |
| Minimum regulatory requirement | | $ | 200,114 | | | | 8.00 | % | | $ | 199,554 | | | | 8.00 | % |
| | | | | | | | | | | | | | | | | |
| Avidbank | | $ | 319,359 | | | | 12.80 | % | | $ | 309,703 | | | | 12.45 | % |
| Minimum requirement for "Well-Capitalized" institution | | $ | 249,406 | | | | 10.00 | % | | $ | 248,735 | | | | 10.00 | % |
| Minimum regulatory requirement | | $ | 199,525 | | | | 8.00 | % | | $ | 198,988 | | | | 8.00 | % |
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