| Document And Entity Information | Jan. 27, 2023 |
| Document Information [Line Items] | |
| Entity, Registrant Name | Isoray, Inc. |
| Document, Type | 8-K |
| Document, Period End Date | Jan. 27, 2023 |
| Entity, Incorporation, State or Country Code | DE |
| Entity, File Number | 001-33407 |
| Entity, Tax Identification Number | 41-1458152 |
| Entity, Address, Address Line One | 350 Hills Street, Suite 106 |
| Entity, Address, City or Town | Richland |
| Entity, Address, State or Province | WA |
| Entity, Address, Postal Zip Code | 99354 |
| City Area Code | 509 |
| Local Phone Number | 375-1202 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | ISR |
| Security Exchange Name | NYSE |
| Entity, Emerging Growth Company | false |
| Amendment Flag | false |
| Entity, Central Index Key | 0000728387 |
