Segment, Geographic, Product and Significant Customer Information - Revenue Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Net revenues:
Total net revenues	$ 67,100	$ 82,313
United States [Member]
Net revenues:
Total net revenues	16,874	6,738
China [Member]
Net revenues:
Total net revenues	14,361	8,042
South Korea [Member]
Net revenues:
Total net revenues	13,968	37,818
Taiwan [Member]
Net revenues:
Total net revenues	11,288	1,060
Japan [Member]
Net revenues:
Total net revenues	4,318	13,379
Singapore [Member]
Net revenues:
Total net revenues	1,551	12,155
Other [Member]
Net revenues:
Total net revenues	$ 4,740	$ 3,121