Summary of Significant Accounting Policies - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 years	Dec. 31, 2010	Dec. 31, 2009
Significant Accounting Policies [Line Items]
Accounts receivable, allowance for doubtful accounts	$ 10,381	$ 14,636	$ 14,235
Other intangible assets, maximum estimated useful lives - in years	15
Net foreign currency gains	$ 1,930	$ 2,026	$ 1,418