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

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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; classified as noncurrent.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-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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Deferred Costs To Obtain Customer Contracts Narratives (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 27, 2019	Sep. 28, 2018	Sep. 27, 2019	Sep. 28, 2018	Dec. 28, 2018
Capitalized Contract Cost [Line Items]
Deferred costs to obtain customer contracts	$ 41.9		$ 41.9		$ 41.3
Deferred Commission [Member]
Capitalized Contract Cost [Line Items]
Impairment loss related to deferred commissions	0.0	$ 0.0	0.0	$ 0.0
Sales And Marketing Expense [Member]
Capitalized Contract Cost [Line Items]
Amortization expense related to deferred costs to obtain customer contracts	$ 5.3	$ 6.2	$ 16.2	$ 17.2