Revenue Recognition (Narrative) (Details) $ in Millions	3 Months Ended
Apr. 01, 2018 USD ($) region segment	Apr. 02, 2017 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Shipping and handling costs associated with outbound freight	$ 2.7	$ 2.3
Revenue deferred due to unsatisfied performance obligations	13.5
Revenue recognized for satisfaction of performance obligations over time	10.8
Recognized revenue that was included in contract liability balance at beginning of period	$ 9.4
Number of geographic regions in which the Company conducts business \| region	3
Number of operating segments \| segment	3
Number of reportable segments \| segment	3
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
General length of subscription contracts	30 days
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
General length of subscription contracts	12 months

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Number of Geographic Regions

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Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (b)
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Amount of revenue recognized from performance obligation satisfied or partially satisfied in previous reporting periods. Includes, but is not limited to, change in transaction price.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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Period in which remaining performance obligation is expected to be recognized as revenue, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Fees charged to customers for the delivery, generally by postal or freight service providers, of product or goods purchased.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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