Annual report pursuant to Section 13 and 15(d)

Document And Entity Information

Document And Entity Information - USD ($)
12 Months Ended
Jan. 02, 2021
Feb. 26, 2021
Jun. 27, 2020
Document Information [Line Items]      
Entity Central Index Key 0000896264    
Entity Registrant Name USANA HEALTH SCIENCES INC    
Amendment Flag false    
Current Fiscal Year End Date --01-02    
Document Fiscal Period Focus FY    
Document Fiscal Year Focus 2020    
Document Type 10-K    
Document Annual Report true    
Document Period End Date Jan. 02, 2021    
Document Transition Report false    
Entity File Number 001-35024    
Entity Incorporation, State or Country Code UT    
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, Par Value $0.001 per share    
Trading Symbol USNA    
Security Exchange Name NYSE    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
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 Public Float     $ 817,064,134
Entity Common Stock, Shares Outstanding   20,852,268  
ICFR Auditor Attestation Flag true