Derivative Instruments - Effects of Gains and Losses from Derivative Instruments on Condensed Consolidated Financial Statements (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended	9 Months Ended	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Jun. 30, 2012	Sep. 30, 2013	Sep. 30, 2013 Derivatives not designated as hedging instruments [Member] Call Option [Member]	Sep. 30, 2012 Derivatives not designated as hedging instruments [Member] Call Option [Member]	Sep. 30, 2013 Derivatives not designated as hedging instruments [Member] Call Option [Member]	Sep. 30, 2012 Derivatives not designated as hedging instruments [Member] Call Option [Member]	Sep. 30, 2013 Derivatives designated as fair value hedges [Member] Put/Call Option [Member]	Sep. 30, 2012 Derivatives designated as fair value hedges [Member] Put/Call Option [Member]	Sep. 30, 2013 Derivatives designated as fair value hedges [Member] Put/Call Option [Member]	Sep. 30, 2012 Derivatives designated as fair value hedges [Member] Put/Call Option [Member]	Sep. 30, 2013 Revenue [Member] Forward Contracts [Member]	Sep. 30, 2012 Revenue [Member] Forward Contracts [Member]	Sep. 30, 2013 Revenue [Member] Forward Contracts [Member]	Sep. 30, 2012 Revenue [Member] Forward Contracts [Member]	Sep. 30, 2013 Revenue [Member] Derivatives not designated as hedging instruments [Member] Forward Contracts [Member]	Sep. 30, 2012 Revenue [Member] Derivatives not designated as hedging instruments [Member] Forward Contracts [Member]	Sep. 30, 2013 Revenue [Member] Derivatives not designated as hedging instruments [Member] Forward Contracts [Member]	Sep. 30, 2012 Revenue [Member] Derivatives not designated as hedging instruments [Member] Forward Contracts [Member]	Sep. 30, 2013 Cost of Sales [Member] Derivatives designated as fair value hedges [Member] Put/Call Option [Member]	Sep. 30, 2012 Cost of Sales [Member] Derivatives designated as fair value hedges [Member] Put/Call Option [Member]	Sep. 30, 2013 Cost of Sales [Member] Derivatives designated as fair value hedges [Member] Put/Call Option [Member]	Sep. 30, 2012 Cost of Sales [Member] Derivatives designated as fair value hedges [Member] Put/Call Option [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on derivatives	$ 81	$ 84	$ (137)	$ 183	$ 38	$ 0	$ 29	$ 0	$ (43)	$ (2)	$ (57)	$ (17)	$ 86	$ 86	$ 239	$ (147)	$ 86	$ 86	$ 239	$ (147)	$ 0	$ 0	$ (28)	$ 27