Assets for Each Reportable Segment (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 28, 2013	Dec. 31, 2012
Segment Reporting, Asset Reconciling Item [Line Items]
Cash, cash equivalents and investments	$ 85,720	$ 92,169
Deferred income taxes	13,189	12,176
Other current assets	1,011	1,870
Common property, plant and equipment	1,283	1,211
Other assets	478	649
Consolidated total assets	161,353	172,503
Operating Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Consolidated total assets	59,672	64,428
Operating Segments | Equipment
Segment Reporting, Asset Reconciling Item [Line Items]
Consolidated total assets	39,825	37,376
Operating Segments | Intevac Photonics
Segment Reporting, Asset Reconciling Item [Line Items]
Consolidated total assets	$ 19,847	$ 27,052