Schedule of Fair Value of Marketable Securities and Foreign Currency Contracts (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed income available-for-sale securities	$ 252,040	[1]	$ 260,792	[1]
Foreign currency forward contracts	7,131	[2]	4,158	[2]
Foreign currency forward contracts	5,612	[3]	3,273	[3]
Quoted Prices in Active Markets for Identical Assets, Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed income available-for-sale securities	200	[1]	795	[1]
Foreign currency forward contracts		[2]
Foreign currency forward contracts		[3]
Significant Other Observable Inputs, Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed income available-for-sale securities	251,840	[1]	259,997	[1]
Foreign currency forward contracts	7,131	[2]	4,158	[2]
Foreign currency forward contracts	$ 5,612	[3]	$ 3,273	[3]

[1] Included in cash and cash equivalents, and short and long-term investments on the Company’s condensed consolidated balance sheets.

[2] Included in short-term derivative assets as prepaid expenses and other current assets on the Company’s condensed consolidated balance sheets.

[3] Included in short-term derivative liabilities as other accrued liabilities on the Company’s condensed consolidated balance sheets.