Revenue from Contracts with Customers (Disaggregation of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 102,715	$ 94,137	$ 201,338	$ 198,724
Asia
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	77,899	64,946	149,820	138,404
Europe
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	12,162	10,579	24,304	21,659
Total revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	12,654	18,612	27,214	38,661
Product revenue - Distributors
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	88,790	71,570	174,747	145,650
Product revenue - Direct
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	9,504	11,598	18,656	30,187
Licensing and services revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 4,421	$ 10,969	$ 7,935	$ 22,887