Activity in Inventory Reserve Allowance (Detail) - Inventory Valuation Reserve - USD ($) $ in Thousands	12 Months Ended
Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Inventory [Line Items]
Beginning Balance	$ 673	$ 1,090	$ 238
Charged to Expense	740	1,684	1,324
Write-Offs and Other	1,270	2,101	472
Ending Balance	$ 143	$ 673	$ 1,090

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.

No definition available.

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- Definition

Amount of valuation and qualifying accounts and reserves.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SX 210.12-09)
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

+ Details

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- Definition

Amount of increase in valuation and qualifying accounts and reserves from charge to cost and expense.

+ References

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- Definition

Amount of decrease in valuation and qualifying accounts and reserves.

+ References

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