Depreciation and Amortization (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 02, 2016	Jan. 03, 2015	Dec. 31, 2013
Segment Reporting Information [Line Items]
Depreciation and amortization	$ 4,597	$ 4,705	$ 4,518
Operating Segments
Segment Reporting Information [Line Items]
Depreciation and amortization	4,180	4,213	4,046
Operating Segments | Thin-film Equipment Segment
Segment Reporting Information [Line Items]
Depreciation and amortization	2,443	2,379	2,146
Operating Segments | Photonics
Segment Reporting Information [Line Items]
Depreciation and amortization	1,737	1,834	1,900
Unallocated Amount to Segment
Segment Reporting Information [Line Items]
Depreciation and amortization	$ 417	$ 492	$ 472