Schedule of Tax Effects Allocated to Each Component of Other Comprehensive (Loss) Income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Components Of Other Comprehensive Income Loss [Line Items]
Foreign currency translation adjustment	$ 5,073	$ 8,454	$ (8,367)	$ (212)
Unrealized gain on available-for-sale securities	27	28	24	51
Income tax expense	(9)	(13)	(9)	(24)
Unrealized gain on available-for-sale securities, net of tax	18	15	15	27
Other comprehensive income (loss)	$ 5,091	$ 8,469	$ (8,352)	$ (185)