Description Of Business And Accounting Policies (Narrative) (Details)	12 Months Ended
	Jan. 01, 2021 USD ($) segment	Jan. 03, 2020 USD ($)	Dec. 28, 2018 USD ($)
Accounting Policies [Line Items]
Reportable segments | segment	4
Subscription revenue term	3 years
Unbilled receivables	$ 138,700,000	$ 129,500,000
Depreciation expense	39,700,000	39,400,000	$ 35,600,000
Accrued warranty expenses	13,800,000	16,300,000
Advertising expense	28,600,000	42,700,000	42,700,000
Research and development expense with third party funding earned	$ 16,300,000	16,500,000	$ 19,500,000
Land, building, furniture, and leasehold improvements
Accounting Policies [Line Items]
Useful life of asset, in years	39 years
Minimum
Accounting Policies [Line Items]
Product Warranty Term	1 year
Post contract	1 year
Amortization period	3 years
Maturity period of derivative financial instrument, minimum, in months	1 month
Estimated useful lives goodwill and purchased intangible assets, in years	3 years
Warranty periods for products sold	1 year
Minimum | Machinery and equipment
Accounting Policies [Line Items]
Useful life of asset, in years	4 years
Minimum | Furniture and fixtures
Accounting Policies [Line Items]
Useful life of asset, in years	5 years
Minimum | Computer equipment and software
Accounting Policies [Line Items]
Useful life of asset, in years	2 years
Minimum | Internal-use of software
Accounting Policies [Line Items]
Useful life of asset, in years	2 years
Maximum
Accounting Policies [Line Items]
Product Warranty Term	2 years
Post contract	3 years
Amortization period	7 years
Maturity period of derivative financial instrument, minimum, in months	2 months
Estimated useful lives goodwill and purchased intangible assets, in years	10 years
Warranty periods for products sold	2 years
Maximum | Machinery and equipment
Accounting Policies [Line Items]
Useful life of asset, in years	6 years
Maximum | Furniture and fixtures
Accounting Policies [Line Items]
Useful life of asset, in years	10 years
Maximum | Computer equipment and software
Accounting Policies [Line Items]
Useful life of asset, in years	5 years
Maximum | Internal-use of software
Accounting Policies [Line Items]
Useful life of asset, in years	5 years
Weighted average
Accounting Policies [Line Items]
Estimated useful lives goodwill and purchased intangible assets, in years	7 years
Forward contracts
Accounting Policies [Line Items]
Derivative financial instruments accounted for as hedges	$ 0	$ 0