Amortization Expense of Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 28, 2018	Sep. 29, 2017	Sep. 28, 2018	Sep. 29, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization expense – cost of revenue	$ 2,492	$ 2,741	$ 7,461	$ 6,078
Amortization expense – operating expenses	3,947	3,217	11,538	9,413
Total amortization expense	$ 6,439	$ 5,958	$ 18,999	$ 15,491

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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