The portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments representing (a) the amount of the hedge ineffectiveness and (b) the amount, if any, excluded from the assessment of hedge effectiveness.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-Subparagraph (a)(1),(2)
-URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986

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- Definition

Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments.

+ References

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+ References

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Derivatives - Additional Information (Detail) - USD ($)	12 Months Ended
Derivatives - Additional Information (Detail) - USD ($)	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Derivative [Line Items]
Derivative financial instruments or related activity	$ 0	$ 0
Aluminum Contracts [Member] \| Nonoperating Income (Expense) [Member]
Derivative [Line Items]
Other expense, net			$ 400,000