Financial Statement Components - Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 24, 2016	Sep. 30, 2017	Sep. 24, 2016
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning of period			$ 243,774
Current period change	$ 779	$ 520	3,468	$ 2,091
End of period	274,485		274,485
Foreign Currency Translations [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning of period			(5,817)
Current period change			3,470
End of period	(2,347)		(2,347)
Defined Benefit Pension Plans [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning of period			(227)
End of period	(227)		(227)
Unrealized Income (Loss) on Investment [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning of period			(2)
Current period change			(2)
End of period	(4)		(4)
Accumulated Other Comprehensive Income (Loss) [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning of period			(6,046)
End of period	$ (2,578)		$ (2,578)