Net Gains or Losses Recorded in Other Income and Consolidated Statements of Income Relating to Foreign Exchange Contracts Not Designated as Hedges (Detail) (Derivatives Not Designated as Hedging Instruments, USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Derivatives Not Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Gains(losses)recognized in other income,net	$ 1,489	$ (3,389)	$ (1,904)	$ (1,997)