Annual report pursuant to Section 13 and 15(d)

Document And Entity Information

Document And Entity Information - USD ($)
12 Months Ended
Dec. 29, 2018
Feb. 22, 2019
Jun. 30, 2018
Document And Entity Information [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 29, 2018    
Document Fiscal Period Focus FY    
Entity Central Index Key 0000896264    
Entity Registrant Name USANA HEALTH SCIENCES INC    
Current Fiscal Year End Date --12-29    
Document Fiscal Year Focus 2018    
Entity Filer Category Large Accelerated Filer    
Entity Current Reporting Status Yes    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Common Stock, Shares Outstanding   23,317,366  
Entity Public Float     $ 1,581,107,286
Trading Symbol usna    
Entity Emerging Growth Company false    
Entity Small Business false    
Entity Shell Company false