Document and Entity Information - shares	6 Months Ended
	Jul. 02, 2016	Aug. 02, 2016
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jul. 02, 2016
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	Q2
Trading Symbol	IVAC
Entity Registrant Name	INTEVAC INC
Entity Central Index Key	0001001902
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		20,923,678