Deferred Costs to Obtain Customer Contracts (Narrative) (Details) - USD ($)	12 Months Ended
	Jan. 01, 2021	Jan. 03, 2020	Dec. 28, 2018
Capitalized Contract Cost [Line Items]
Deferred costs to obtain customer contracts	$ 51,300,000	$ 45,400,000
Deferred Commission
Capitalized Contract Cost [Line Items]
Impairment loss related to deferred commissions	0	0	$ 0
Selling and Marketing Expense
Capitalized Contract Cost [Line Items]
Amortization expense related to deferred costs to obtain customer contracts	$ 22,800,000	$ 22,300,000	$ 23,600,000