Change in the Carrying Amount of Goodwill (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Goodwill [Line Items]
Beginning Balance	$ 359,116	$ 361,666
Acquisitions	2,009	0
Translation	(1,437)	(2,550)
Ending Balance	$ 359,688	$ 359,116