A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.4)
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-Name Accounting Standards Codification
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Amount of increase (decrease) in the allowance for doubtful accounts.

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

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Amount of expense related to write-down of receivables to the amount expected to be collected. Includes, but is not limited to, accounts receivable and notes receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=82913815&loc=SL49130534-203044

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
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Basis of Presentation and Significant Accounting Policies (Concentration Risk) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016	Dec. 31, 2016
Risks and Uncertainties [Abstract]
Allowance for doubtful accounts	$ 9.4		$ 9.4		$ 9.3
Increase in allowance for doubtful accounts					$ 9.0
Bad debt expense		$ 7.5		$ 7.5
Revenue \| Sell-Through Distributors Concentration Risk
Risks and Uncertainties [Abstract]
Concentration Risk	68.00%	62.00%	65.00%	58.00%	60.00%
Product revenue \| Sell-Through Distributors Concentration Risk
Risks and Uncertainties [Abstract]
Concentration Risk	72.00%		71.00%		66.00%
Top Five Customers \| Revenue \| Customer Concentration Risk
Risks and Uncertainties [Abstract]
Concentration Risk	23.00%	32.00%	28.00%	25.00%
Largest Customer \| Revenue \| Customer Concentration Risk
Risks and Uncertainties [Abstract]
Concentration Risk	5.00%	14.00%	9.00%	7.00%
Largest Distributor Group \| Trade receivables \| Sell-Through Distributors Concentration Risk
Risks and Uncertainties [Abstract]
Concentration Risk			41.00%		38.00%
Second Largest Distributor Group \| Trade receivables \| Sell-Through Distributors Concentration Risk
Risks and Uncertainties [Abstract]
Concentration Risk			28.00%		24.00%