Fair Value of Financial Instruments - Fair Value of Gross Position of Derivative Contracts in Condensed Consolidated Balance Sheets (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014 Accrued Liabilities [Member]	Dec. 31, 2013 Other Current Assets [Member]	Jun. 30, 2014 Designated as Hedging Instruments [Member] Accrued Liabilities [Member]	Jun. 30, 2014 Designated as Hedging Instruments [Member] Accrued Liabilities [Member] Gross Amounts Recognized [Member]	Jun. 30, 2014 Designated as Hedging Instruments [Member] Accrued Liabilities [Member] Gross Amounts Offset [Member]	Dec. 31, 2013 Designated as Hedging Instruments [Member] Other Current Assets [Member]	Dec. 31, 2013 Designated as Hedging Instruments [Member] Other Current Assets [Member] Gross Amounts Recognized [Member]	Dec. 31, 2013 Designated as Hedging Instruments [Member] Other Current Assets [Member] Gross Amounts Offset [Member]	Jun. 30, 2014 Not Designated as Hedging Instruments [Member] Accrued Liabilities [Member]	Jun. 30, 2014 Not Designated as Hedging Instruments [Member] Accrued Liabilities [Member] Gross Amounts Recognized [Member]	Dec. 31, 2013 Not Designated as Hedging Instruments [Member] Other Current Assets [Member]	Dec. 31, 2013 Not Designated as Hedging Instruments [Member] Other Current Assets [Member] Gross Amounts Recognized [Member]
Derivatives, Fair Value [Line Items]
Derivatives (Assets)/ liabilities as hedging instruments	$ (2,856)	$ 349	$ (2,691)	$ (3,802)	$ 1,111	$ 470	$ 2,702	$ (2,232)	$ (165)	$ (165)	$ (121)	$ (121)