Segment and Geographic Information - Revenue by Geographic Area (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 23, 2016	Sep. 25, 2015	Sep. 23, 2016	Sep. 25, 2015
Segment Reporting Information [Line Items]
Sales	$ 146,154	$ 122,816	$ 388,214	$ 365,683
United States [Member]
Segment Reporting Information [Line Items]
Sales	83,296	82,708	217,026	252,138
China [Member]
Segment Reporting Information [Line Items]
Sales	6,961	1,017	11,593	18,267
Singapore [Member]
Segment Reporting Information [Line Items]
Sales	39,310	29,952	115,353	77,354
Austria [Member]
Segment Reporting Information [Line Items]
Sales	7,994	5,059	25,805	5,059
Other [Member]
Segment Reporting Information [Line Items]
Sales	$ 8,593	$ 4,080	$ 18,437	$ 12,865