Goodwill and Intangible Assets - Purchased Intangible Assets (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 29, 2018	Dec. 30, 2017
Intangible assets with finite lives:
Gross Carrying Amount	$ 144,100	$ 155,758
Accumulated Amortization	(77,956)	(63,570)
Net Carrying Amount	$ 66,144	$ 92,188
Weighted average remaining useful life (in years)	3 years 3 months 4 days	3 years 10 months 8 days
Customer relationships
Intangible assets with finite lives:
Gross Carrying Amount	$ 47,229	$ 51,050
Accumulated Amortization	(18,311)	(15,007)
Net Carrying Amount	$ 28,918	$ 36,043
Weighted average remaining useful life (in years)	4 years 10 months 21 days	5 years 7 months 20 days
Developed technology
Intangible assets with finite lives:
Gross Carrying Amount	$ 96,871	$ 104,708
Accumulated Amortization	(59,645)	(48,563)
Net Carrying Amount	$ 37,226	$ 56,145
Weighted average remaining useful life (in years)	1 year 11 months 27 days	2 years 8 months 15 days