Stock-Based Compensation Expense Recognized In Consolidated Statements Of Operations (Detail) (USD $)	3 Months Ended
	Mar. 31, 2012		Mar. 31, 2011
Component of Operating Other Cost and Expense [Line Items]
Stock-based compensation expense	$ 10,939,000	[1]	$ 9,162,000	[1]
Cost of services and product development
Component of Operating Other Cost and Expense [Line Items]
Stock-based compensation expense	5,300,000		4,500,000
Selling, general and administrative
Component of Operating Other Cost and Expense [Line Items]
Stock-based compensation expense	$ 5,600,000		$ 4,700,000

[1] Includes charges of $3.0 million and $2.5 million for the three months ended March 31, 2012 and 2011 respectively, related to awards to retirement-eligible employees, since a portion of the awards vest immediately.