Segment, Geographic, and Significant Customer Information - Long-lived Tangible Assets (Details) - USD ($) $ in Thousands	Dec. 29, 2018	Dec. 30, 2017
Long-lived tangible assets:
Total long-lived tangible assets	$ 47,900	$ 44,810
United States [Member]
Long-lived tangible assets:
Total long-lived tangible assets	46,325	43,427
Taiwan [Member]
Long-lived tangible assets:
Total long-lived tangible assets	275	510
South Korea [Member]
Long-lived tangible assets:
Total long-lived tangible assets	420	576
Japan [Member]
Long-lived tangible assets:
Total long-lived tangible assets	59	60
Singapore [Member]
Long-lived tangible assets:
Total long-lived tangible assets	618	92
All Other [Member]
Long-lived tangible assets:
Total long-lived tangible assets	$ 203	$ 145