v3.26.1
Note 2 - Summary of Significant Accounting Policies (Details Textual)
6 Months Ended
Jun. 06, 2025
USD ($)
Jun. 30, 2026
USD ($)
shares
Dec. 31, 2025
USD ($)
Aug. 05, 2025
USD ($)
Oct. 22, 2021
USD ($)
Accounts Receivable, Allowance for Credit Loss, Current   $ 713,000 $ 700,000    
Inventory Valuation Reserves   0 0    
Number of Patents Acquired         3
Intangible Asset, Excluding Goodwill, after Accumulated Amortization         $ 34,000
Contract with Customer, Liability, Current   46,000 280,000    
Contract with Customer, Liability, Revenue Recognized   234,000      
Customer Deposit Liability, Current   83,000 189,000    
Unrecognized Tax Benefits   0 $ 0    
Operating Lease, Weighted Average Discount Rate, Percent     18.00%    
Operating Lease, Right-of-Use Asset   927,000 $ 1,028,000    
Operating Lease, Liability   977,000 1,074,000    
Finance Lease, Right-of-Use Asset, after Accumulated Amortization   282,000 338,000    
Clyra Medical Technologies [Member]          
Finance Lease, Right-of-Use Asset, after Accumulated Amortization   282,000 338,000    
Finance Lease, Liability   $ 311,000 $ 360,000    
Subsidiary, Ownership Percentage, Noncontrolling Owner   52.00% 52.00%    
BioLargo Engineering, Science & Technologies, LLC [Member]          
Subsidiary, Ownership Percentage, Noncontrolling Owner   30.00% 30.00%    
BioLargo Energy Technologies, Inc (BETI) [Member]          
Subsidiary, Ownership Percentage, Noncontrolling Owner   6.00% 5.00%    
BioLargo Consumer Products Group (BCPG) [Member]          
Subsidiary, Ownership Percentage, Noncontrolling Owner   22.00%      
Minimum [Member]          
Property, Plant and Equipment, Useful Life (Year)   3 years      
Maximum [Member]          
Property, Plant and Equipment, Useful Life (Year)   10 years      
BioLargo Energy Technologies, Inc (BETI) [Member]          
Customer Deposit Liability, Current     $ 5,000    
Canadian Government Grants [Member] | Minimum [Member]          
Grant Term (Month)   6 months      
Canadian Government Grants [Member] | Maximum [Member]          
Grant Term (Month)   18 months      
CANADA          
Customer Deposit Liability, Current   $ 80,000 $ 80,000    
Share-Based Payment Arrangement, Option [Member]          
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares) | shares   71,947,417      
Warrant [Member]          
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares) | shares   27,529,783      
Royalty Receivable [Member]          
Financing Receivable, before Allowance for Credit Loss       $ 463,520  
Financial Asset, Past Due [Member] | Product Invoice Receivable [Member]          
Financing Receivable, before Allowance for Credit Loss $ 2,385,468        
Receivable with Imputed Interest, Effective Yield (Interest Rate) 10.00%        
Financial Asset, Past Due [Member] | Royalty Receivable [Member]          
Financing Receivable, before Allowance for Credit Loss $ 1,378,141