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://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
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-Section 45
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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Goodwill, Other Intangible Assets and Other Assets - Other Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 35,640		$ 35,640		$ 27,000
Intangible assets accumulated amortization	20,325		20,325		14,793
Intangible Assets, Net	15,315		15,315		12,207
Amortization of Acquired Intangible Assets	2,300	$ 900	5,500	$ 2,600
Completed technology
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	26,900		26,900		26,900
Intangible assets accumulated amortization	17,286		17,286		14,693
Intangible Assets, Net	9,614		9,614		12,207
Trade Names
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	100		100		100
Intangible assets accumulated amortization	100		100		100
Intangible Assets, Net	0		0		0
Customer-Related Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	4,490		4,490		0
Intangible assets accumulated amortization	173		173		0
Intangible Assets, Net	4,317		4,317		0
Distribution Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	4,150		4,150		0
Intangible assets accumulated amortization	2,766		2,766		0
Intangible Assets, Net	$ 1,384		$ 1,384		$ 0
Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life			9 months