Summary of Changes to Goodwill (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended				6 Months Ended
	Mar. 31, 2012	Mar. 31, 2012 Applications	Mar. 31, 2012 Scores	Sep. 30, 2011 Scores	Mar. 31, 2012 Tools
Beginning Balance	$ 664,688	$ 451,205	$ 146,648	$ 146,648	$ 66,835
Foreign currency translation adjustment	2,410	1,986			424
Ending Balance	$ 667,098	$ 453,191	$ 146,648	$ 146,648	$ 67,259