v3.3.1.900
Document and Entity Information - USD ($)
12 Months Ended
Jan. 02, 2016
Feb. 17, 2016
Jul. 04, 2015
Document Information [Line Items]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Jan. 02, 2016    
Document Fiscal Year Focus 2015    
Document Fiscal Period Focus FY    
Trading Symbol IVAC    
Entity Registrant Name INTEVAC INC    
Entity Central Index Key 0001001902    
Current Fiscal Year End Date --01-02    
Entity Well-known Seasoned Issuer No    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Filer Category Accelerated Filer    
Entity Common Stock, Shares Outstanding   20,649,857  
Entity Public Float     $ 106,155,213