Forward Contracts with Notional Values (Detail) (Forward Contracts) In Thousands, unless otherwise specified	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 Euro EUR (€)	Sep. 30, 2012 Euro EUR (€)	Sep. 30, 2013 Euro EUR (€)	Sep. 30, 2012 Euro EUR (€)	Sep. 30, 2013 British pound GBP (£)	Sep. 30, 2012 British pound GBP (£)	Sep. 30, 2013 British pound GBP (£)	Sep. 30, 2012 British pound GBP (£)	Sep. 30, 2013 Australian Dollar AUD	Sep. 30, 2013 Australian Dollar AUD	Sep. 30, 2013 Indian Rupees INR	Sep. 30, 2013 Indian Rupees INR
Derivative [Line Items]
Notional amount	€ 28,500	€ 21,700	€ 61,000	€ 48,900	£ 26,000	£ 16,000	£ 59,500	£ 39,000	15,500	15,500	460,000	460,000