Derivative Financial Instruments (Schedule of Effects and Locations of Gains or Losses Recognized in Income) (Details) - USD ($) $ in Thousands	3 Months Ended
Apr. 01, 2018	Apr. 02, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Net revenue	$ 344,973	$ 323,657
Cost of revenue	240,468	226,725
Research and development	28,947	22,683
Sales and marketing	43,658	38,229
General and administrative	16,638	$ 13,194
Net revenue \| Cash Flow Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on cash flow hedge	(2,568)
Cost of revenue \| Cash Flow Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on cash flow hedge	6
Research and development \| Cash Flow Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on cash flow hedge	99
Sales and marketing \| Cash Flow Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on cash flow hedge	230
General and administrative \| Cash Flow Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on cash flow hedge	$ 41

The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2(a),(d))
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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
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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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The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.4)
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The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

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-Publisher FASB
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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

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The aggregate total amount of expenses directly related to the marketing or selling of products or services.

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