Related Party Transaction - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Nov. 12, 2015	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Related Party Transaction [Line Items]
Shares of common stock repurchased			3,419,000	1,185,000
Cost of stock repurchased			$ 18,503	$ 8,302
NRC
Related Party Transaction [Line Items]
Shares of common stock repurchased	1,483,171
Outstanding common stock repurchased percentage	6.80%
Purchase price per share	$ 4.98
Cost of stock repurchased	$ 7,400
Outstanding shares ownership percentage	3.60%
Related party transaction description		Matthew Drapkin, a member of Intevac's Board of Directors, is a principal of NRC and a member of BC Advisors, LLC, which is the general partner of NRC. NRC continues to beneficially own approximately 3.6% of the outstanding shares of Intevac's common stock subsequent to the transaction.