Derivative Financial Instruments - Summary of Outstanding Commodity Derivative Agreements (Detail) - Commodity Hedging Agreements [Member] - USD ($)	6 Months Ended	12 Months Ended
Jun. 30, 2019	Dec. 30, 2018
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Notional amount of outstanding commodity derivative agreements	$ 167,630,000	$ 168,388,000
Latest maturity date of outstanding commodity derivative agreements	2020-12	2019-12

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.

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