Derivative Financial Instruments and Fair Value Measurements - Derivatives Recorded at Fair Value in Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 317	$ 2
Derivative Liability, Fair Value, Gross Liability	10,713	4,392
Current | Not Designated As Hedging Instruments | Commodities Contracts
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	317	2
Derivative Liability, Fair Value, Gross Liability	10,023	4,392
Non-current | Not Designated As Hedging Instruments | Commodities Contracts
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	$ 690	$ 0