Accounting Policies (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 28, 2018 USD ($) segment	Dec. 29, 2017 USD ($)		Dec. 30, 2016 USD ($)
Accounting Policies [Line Items]
Business Combination Valuation Remeasurement Window	1 year
Number of Reportable Segments | segment	4
Subscription revenue term	5 years
Allowance for Doubtful Accounts Receivable, Current	$ 4,600	$ 3,600		$ 5,000
Advertising expense	42,700	37,200		37,200
Research and Development expense with third party funding earned	19,500	18,100		13,000
Net Cash Provided by Operating Activities	486,700	429,700	[1]	431,100	[1]
Net Cash Provided by (Used in) Investing Activities, Continuing Operations	(1,649,600)	(371,200)	[1]	(146,900)	[1]
Net Cash Provided by (Used in) Financing Activities, Continuing Operations	$ 989,400	66,500	[1]	(177,300)	[1]
Building [Member]
Accounting Policies [Line Items]
Useful life of asset, in years	39 years
Leasehold Improvements [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	the life of the lease
Minimum [Member]
Accounting Policies [Line Items]
Post Contract Support Term	1 year
Capitalized Contract Cost, Amortization Period	3 years
Warranty periods for products sold	1 year
Maturity period of derivative financial instrument, minimum, in months	1 month
Estimated useful lives goodwill and purchased intangible assets, in years	4 years
Minimum [Member] | Machinery And Equipment [Member]
Accounting Policies [Line Items]
Useful life of asset, in years	4 years
Minimum [Member] | Furniture And Fixtures [Member]
Accounting Policies [Line Items]
Useful life of asset, in years	5 years
Minimum [Member] | Computer Equipment And Software [Member]
Accounting Policies [Line Items]
Useful life of asset, in years	2 years
Minimum [Member] | Internal-Use Of Software [Member]
Accounting Policies [Line Items]
Useful life of asset, in years	2 years
Maximum [Member]
Accounting Policies [Line Items]
Post Contract Support Term	3 years
Capitalized Contract Cost, Amortization Period	7 years
Warranty periods for products sold	2 years
Maturity period of derivative financial instrument, minimum, in months	2 months
Investments, Weighted Average Maturity Term	6 months
Estimated useful lives goodwill and purchased intangible assets, in years	10 years
Maximum [Member] | Machinery And Equipment [Member]
Accounting Policies [Line Items]
Useful life of asset, in years	6 years
Maximum [Member] | Furniture And Fixtures [Member]
Accounting Policies [Line Items]
Useful life of asset, in years	10 years
Maximum [Member] | Computer Equipment And Software [Member]
Accounting Policies [Line Items]
Useful life of asset, in years	5 years
Maximum [Member] | Internal-Use Of Software [Member]
Accounting Policies [Line Items]
Useful life of asset, in years	5 years
Weighted Average [Member]
Accounting Policies [Line Items]
Estimated useful lives goodwill and purchased intangible assets, in years	6 years 6 months
Forward Contracts [Member]
Accounting Policies [Line Items]
Derivative Financial Instruments Accounted for as Hedges	$ 0	0
Indemnification Agreement [Member]
Accounting Policies [Line Items]
Loss Contingency Accrual	$ 0	0
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Accounting Policies [Line Items]
Net Cash Provided by Operating Activities		0		0
Net Cash Provided by (Used in) Investing Activities, Continuing Operations		0		0
Net Cash Provided by (Used in) Financing Activities, Continuing Operations		$ 0		$ 0

[1] See Note 2 for a summary of adjustments