Accounting Policies (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 28, 2012	Dec. 30, 2011	Dec. 31, 2010
Accounting Policies [Line Items]
Advertising expense	$ 32,900,000	$ 23,700,000	$ 21,300,000
Third party funding for research and development costs	3,500,000	7,800,000	11,700,000
Depreciation expense	$ 23,691,000	$ 20,509,000	$ 18,198,000
Maturity period of derivative financial instrument, minimum, in months	1 month
Maturity period of derivative financial instrument, maximum, in months	3 months
Furniture And Fixtures [Member]
Accounting Policies [Line Items]
Useful life of asset, in years	5 years
Building [Member]
Accounting Policies [Line Items]
Useful life of asset, in years	40 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]
Estimated useful lives goodwill and purchased intangible assets, in years	1 year
Warranty periods for products sold, in days	90
Minimum [Member] | Machinery And Equipment [Member]
Accounting Policies [Line Items]
Useful life of asset, in years	2 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	3 years
Maximum [Member]
Accounting Policies [Line Items]
Estimated useful lives goodwill and purchased intangible assets, in years	10 years
Warranty periods for products sold, in years	5.5
Maximum [Member] | Machinery And Equipment [Member]
Accounting Policies [Line Items]
Useful life of asset, in years	6 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