Quarterly report pursuant to Section 13 or 15(d)

Document And Entity Information

Document And Entity Information - shares
6 Months Ended
Jun. 27, 2020
Jul. 31, 2020
Document And Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Quarterly Report true  
Document Transition Report false  
Document Period End Date Jun. 27, 2020  
Entity File Number 001-35024  
Document Fiscal Period Focus Q2  
Entity Central Index Key 0000896264  
Entity Registrant Name USANA HEALTH SCIENCES, INC.  
Entity Incorporation, State or Country Code UT  
Current Fiscal Year End Date --01-02  
Document Fiscal Year Focus 2020  
Entity Tax Identification Number 87-0500306  
Entity Address, Address Line One 3838 West Parkway Blvd.  
Entity Address, City or Town Salt Lake City  
Entity Address, State or Province UT  
Entity Address, Postal Zip Code 84120  
City Area Code 801  
Local Phone Number 954-7100  
Title of 12(b) Security Common Stock  
Trading Symbol USNA  
Security Exchange Name NYSE  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   21,020,007