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
	Mar. 31, 2013	Mar. 31, 2012
Derivatives Not Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Gains (losses) recognized in other income, net	$ 577	$ 1,011