Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Aug. 11, 2017
Document Information [Line Items]
Entity Registrant Name	BIOLARGO, INC.
Entity Central Index Key	0000880242
Trading Symbol	blgo
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity Common Stock, Shares Outstanding (in shares)		100,585,385
Document Type	10-Q
Document Period End Date	Jun. 30, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q2
Amendment Flag	false