Note 10 - BioLargo Energy Technologies, Inc. (Details Textual)	3 Months Ended
	Mar. 31, 2023 USD ($) $ / shares shares
BioLargo Energy Technologies, Inc (BETI) [Member]
Investment Owned, Balance, Shares (in shares)	9,050,000
BioLargo Energy Technologies, Inc (BETI) [Member]
Common Stock, Shares, Outstanding, Ending Balance (in shares)	9,325,000
Conversion From BioLargo Note Payable to Shares [Member]
Debt Conversion, Original Debt, Amount | $	$ 50,000
Debt Conversion, Converted Instrument, Shares Issued (in shares)	25,000
BioLargo Energy Technologies, Inc (BETI) [Member]
Stock Issued During Period, Shares, New Issues (in shares)	50,000
Proceeds from Issuance or Sale of Equity | $	$ 100,000
Stock Conversion, Discount on Volume Weighted average Price	20.00%
BioLargo Energy Technologies, Inc (BETI) [Member] | Third Party Investors [Member]
Proceeds from Issuance or Sale of Equity | $	$ 550,000
BioLargo Energy Technologies, Inc (BETI) [Member] | Subsidiaries [Member]
Stock Issued During Period, Shares, New Issues (in shares)	325,000
Sale of Stock, Price Per Share (in dollars per share) | $ / shares	$ 2.00