Note 9 - BioLargo Engineering, Science and Technologies, LLC (Details Textual) - shares |
1 Months Ended | 3 Months Ended | 12 Months Ended |
|---|---|---|---|
Sep. 30, 2017 |
Mar. 31, 2026 |
Dec. 31, 2025 |
|
| Seven Employees Working at BioLargo Engineering, Science & Technologies, LLC [Member] | Vesting on Performance Metrics [Member] | |||
| Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage | 30.00% | 30.00% | |
| Seven Employees Working at BioLargo Engineering, Science & Technologies, LLC [Member] | Non-Qualified Stock Option [Member] | |||
| Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares) | 1,750,000 | ||
| Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) | 5 years | ||
| BioLargo Engineering, Science & Technologies, LLC [Member] | |||
| Subsidiary, Ownership Percentage, Parent | 100.00% | 70.00% |