v3.19.3
Document And Entity Information - shares
3 Months Ended
Sep. 30, 2019
Nov. 14, 2019
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 Emerging Growth Company false  
Entity Small Business true  
Entity Common Stock, Shares Outstanding (in shares)   7,167,314
Entity Shell Company false  
Document Type 10-Q  
Document Period End Date Sep. 30, 2019  
Document Fiscal Year Focus 2020  
Document Fiscal Period Focus Q1  
Amendment Flag false  
Title of 12(b) Security Common Stock, $0.01 par value per share