Commitments and Contingencies - Summary of Warranty Accrual Included in Accrued Liabilities (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 29, 2017	Sep. 30, 2016	Sep. 29, 2017	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Balance at beginning of period	$ 4,142	$ 5,095	$ 4,862	$ 3,913
Balance assumed from TVN acquisition	0	0	0	1,012
Accrual for current period warranties	1,354	1,552	3,849	4,527
Changes in liability related to pre-existing warranties	0	(99)	0	(173)
Warranty costs incurred	(1,155)	(1,469)	(4,370)	(4,200)
Balance at end of period	$ 4,341	$ 5,079	$ 4,341	$ 5,079

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- Definition

Carrying value as of the balance sheet date of obligations incurred through that date and payable for estimated claims under standard and extended warranty protection rights granted to customers.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=68068213&loc=d3e12565-110249

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (c)(5)
-URI http://asc.fasb.org/extlink&oid=68068213&loc=d3e12565-110249

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.15(5))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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- Definition

Amount of increase in the standard and extended product warranty accrual from a business acquisition.

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Amount of increase (decrease) in the standard and extended product warranty accrual from changes in estimates attributable to preexisting product warranties.

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Amount of increase in the standard and extended product warranty accrual from warranties issued.

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Amount of decrease in the standard product warranty accrual from payments made in cash or in kind to satisfy claims under the terms of the standard product warranty. Excludes extended product warranties.

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