Segment, Geographic, Product and Significant Customer Information - Long-lived Tangible Assets (Details) - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Long-lived tangible assets:
Total long-lived tangible assets	$ 44,810	$ 44,226
United States [Member]
Long-lived tangible assets:
Total long-lived tangible assets	43,427	42,688
Taiwan [Member]
Long-lived tangible assets:
Total long-lived tangible assets	510	818
South Korea [Member]
Long-lived tangible assets:
Total long-lived tangible assets	576	554
Japan [Member]
Long-lived tangible assets:
Total long-lived tangible assets	60	57
All Other [Member]
Long-lived tangible assets:
Total long-lived tangible assets	$ 237	$ 109