Stock-Based Compensation Expense Recognized in the Consolidated Statements of Operations (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Component of Operating Other Cost and Expense [Line Items]
Stock-based compensation expense	$ 7,800,000	$ 7,300,000	$ 24,750,000	$ 23,298,000
Cost of services and product development
Component of Operating Other Cost and Expense [Line Items]
Stock-based compensation expense	3,300,000	3,100,000	11,300,000	10,900,000
Selling, general and administrative
Component of Operating Other Cost and Expense [Line Items]
Stock-based compensation expense	$ 4,500,000	$ 4,200,000	$ 13,500,000	$ 12,400,000