Revenue from Unaffiliated Customers by Geographic Region/Country (Detail) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Segment Reporting Information [Line Items]
Total net revenues		$ 24,769	$ 26,726	$ 30,963	$ 30,388	$ 28,982	$ 22,559	$ 14,918	$ 13,664	$ 112,847	$ 80,124	$ 75,160
United States
Segment Reporting Information [Line Items]
Total net revenues										37,311	42,048	49,034
Asia
Segment Reporting Information [Line Items]
Total net revenues	[1]									73,525	37,143	23,855
Europe
Segment Reporting Information [Line Items]
Total net revenues										884	$ 933	$ 2,271
Rest of World
Segment Reporting Information [Line Items]
Total net revenues										$ 1,127

[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. Net trade revenues in Rest of World includes technology development revenue in Australia.