v3.19.2
Document And Entity Information - USD ($)
12 Months Ended
Jun. 30, 2019
Sep. 18, 2019
Dec. 31, 2018
Document Information [Line Items]      
Entity Registrant Name NATURAL ALTERNATIVES INTERNATIONAL INC    
Entity Central Index Key 0000787253    
Trading Symbol naii    
Current Fiscal Year End Date --06-30    
Entity Filer Category Non-accelerated Filer    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Well-known Seasoned Issuer No    
Entity Emerging Growth Company false    
Entity Small Business true    
Entity Common Stock, Shares Outstanding (in shares)   7,225,072  
Entity Public Float     $ 54,141,271
Entity Shell Company false    
Document Type 10-K    
Document Period End Date Jun. 30, 2019    
Document Fiscal Year Focus 2019    
Document Fiscal Period Focus FY    
Amendment Flag false    
Title of 12(b) Security Common Stock