Fair Value Measurements - Fair Value of Gross Position of Derivative Contracts in Consolidated Balance Sheets (Detail) - Other Current Assets [Member] - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Derivatives Assets/ (liabilities) as hedging instruments	$ 5,672	$ 5,979
Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivatives Assets/ (liabilities) as hedging instruments	5,267	5,979
Designated as Hedging Instruments [Member] | Gross Amounts Recognized [Member]
Derivatives, Fair Value [Line Items]
Derivatives Assets/ (liabilities) as hedging instruments	5,400	6,483
Designated as Hedging Instruments [Member] | Gross Amounts Offset [Member]
Derivatives, Fair Value [Line Items]
Derivatives Assets/ (liabilities) as hedging instruments	(133)	$ (504)
Not Designated as Hedging Instruments [Member] | Gross Amounts Recognized [Member]
Derivatives, Fair Value [Line Items]
Derivatives Assets/ (liabilities) as hedging instruments	$ 405