| Document And Entity Information | Dec. 02, 2022 |
| Document Information [Line Items] | |
| Entity, Registrant Name | NATURAL ALTERNATIVES INTERNATIONAL, INC. |
| Document, Type | 8-K |
| Document, Period End Date | Dec. 02, 2022 |
| Entity, File Number | 000-15701 |
| Entity, Incorporation, State or Country Code | DE |
| Entity, Tax Identification Number | 84-1007839 |
| Entity, Address, Address Line One | 1535 Faraday Avenue |
| Entity, Address, City or Town | Carlsbad |
| Entity, Address, State or Province | CA |
| Entity, Address, Postal Zip Code | 92008 |
| City Area Code | 760 |
| Local Phone Number | 736-7700 |
| Title of 12(b) Security | Common |
| Trading Symbol | NAII |
| Security Exchange Name | NASDAQ |
| 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 | 0000787253 |
