Deferred costs to obtain customer contracts (Details) - USD ($) $ in Millions	12 Months Ended
Jan. 03, 2020	Dec. 28, 2018	Dec. 29, 2017
Deferred Commission [Member]
Capitalized Contract Cost [Line Items]
Capitalized Contract Cost, Impairment Loss	$ 0.0	$ 0.0	$ 0.0
Other Noncurrent Assets [Member]
Capitalized Contract Cost [Line Items]
Capitalized Contract Cost, Net	45.4	41.3
Selling and Marketing Expense [Member]
Capitalized Contract Cost [Line Items]
Capitalized Contract Cost, Amortization	$ 22.3	$ 23.6	$ 21.3

Amount of amortization expense for asset recognized from cost incurred to obtain or fulfill contract with customer.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=68051541&loc=SL49131252-203054

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- Definition

Amount of impairment loss for asset recognized from cost incurred to obtain or fulfill contract with customer.

+ References

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- Definition

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+ References

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Amount, after accumulated amortization and accumulated impairment loss, of asset recognized from cost incurred to obtain or fulfill contract with customer.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=68051541&loc=SL49131252-203054

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