Segment, Geographic, Product and Significant Customer Information - Net Revenue (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2015 USD ($)	Sep. 27, 2014 USD ($)	Sep. 26, 2015 USD ($) segment	Sep. 27, 2014 USD ($)
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of operating segments | segment			1
Total net revenues:
Total net revenues	$ 45,678	$ 27,133	$ 144,682	$ 126,738
United States [Member]
Total net revenues:
Total net revenues	7,985	5,511	32,115	25,554
South Korea [Member]
Total net revenues:
Total net revenues	6,794	6,327	28,807	30,589
Taiwan [Member]
Total net revenues:
Total net revenues	11,331	640	35,173	11,337
China [Member]
Total net revenues:
Total net revenues	6,731	2,848	12,357	27,694
Japan [Member]
Total net revenues:
Total net revenues	7,778	4,099	15,919	10,005
Other [Member]
Total net revenues:
Total net revenues	$ 5,059	$ 7,708	$ 20,311	$ 21,559