Note 13 - Commitments and Contingencies - Minimum Lease Payments (Details)	Dec. 31, 2022 USD ($)
December 31, 2023	$ 269,000
December 31, 2024	224,000
December 31, 2025	157,000
December 31, 2026	160,000
December 31, 2027	161,000
Thereafter	822,000
Total minimum lease payments	1,793,000
BioLargo/ONM Lease [Member]
December 31, 2023	118,000
December 31, 2024	70,000
Total minimum lease payments	188,000
BLEST Lease [Member]
December 31, 2023	151,000
December 31, 2024	154,000
December 31, 2025	157,000
December 31, 2026	160,000
December 31, 2027	161,000
Thereafter	822,000
Total minimum lease payments	$ 1,605,000

Amount of lessee's undiscounted obligation for lease payment for operating lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 6
-URI https://asc.fasb.org/extlink&oid=128292326&loc=SL77918701-209980

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Amount of lessee's undiscounted obligation for lease payment for operating lease due after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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