Derivative Financial Instruments - Additional Information (Detail) - USD ($)	Feb. 28, 2018	Dec. 31, 2017	Jan. 01, 2017
Commodity Contract [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Notional amount of commodity derivative		$ 59,564,000	$ 13,146,000
Commodity Contract [Member] | Subsequent Event [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Notional amount of commodity derivative	$ 91,700,000
Commodity Hedge Agreements Terminated [Member] | Subsequent Event [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Notional amount of commodity derivative	$ 22,600,000