Revenue from Unaffiliated Customers by Geographic Region/Country (Detail) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Jan. 02, 2016	Oct. 03, 2015	Jul. 04, 2015	Apr. 04, 2015	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Segment Reporting Information [Line Items]
Total net revenues		$ 28,982	$ 22,559	$ 14,918	$ 13,664	$ 16,398	$ 18,418	$ 20,458	$ 19,885	$ 80,124	$ 75,160	$ 65,550
United States
Segment Reporting Information [Line Items]
Total net revenues										42,048	49,034	51,584
Asia
Segment Reporting Information [Line Items]
Total net revenues	[1]									37,143	23,855	9,931
Europe
Segment Reporting Information [Line Items]
Total net revenues										$ 933	$ 2,271	$ 4,035

[1] Revenues are attributable to the geographic area in which Intevac's customers are located. Net trade revenues in Asia include shipments to Singapore, China, Japan and Malaysia.