Document And Entity Information
| Document And Entity Information | Aug. 22, 2024 |
| Document Information [Line Items] | |
| Entity, Registrant Name | Cyanotech Corporation |
| Document, Type | 8-K |
| Document, Period End Date | Aug. 22, 2024 |
| Entity, Incorporation, State or Country Code | NV |
| Entity, File Number | 000-14602 |
| Entity, Tax Identification Number | 91-1206026 |
| Entity, Address, Address Line One | 73-4460 Queen Kaahumanu Highway, Suite #102 |
| Entity, Address, City or Town | Kailua Kona |
| Entity, Address, State or Province | HI |
| Entity, Address, Postal Zip Code | 96740 |
| City Area Code | 808 |
| Local Phone Number | 326-1353 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity, Emerging Growth Company | false |
| Amendment Flag | false |
| Entity, Central Index Key | 0000768408 |