Goodwill and Intangible Assets - Summary of Changes to Goodwill (Detail) $ in Thousands	3 Months Ended
	Dec. 31, 2016 USD ($)
Goodwill [Roll Forward]
Balance at September 30, 2016	$ 798,415
Foreign currency translation adjustment	(8,813)
Balance at December 31, 2016	789,602
Applications
Goodwill [Roll Forward]
Balance at September 30, 2016	582,720
Foreign currency translation adjustment	(8,165)
Balance at December 31, 2016	574,555
Scores
Goodwill [Roll Forward]
Balance at September 30, 2016	146,648
Foreign currency translation adjustment	0
Balance at December 31, 2016	146,648
Decision Management Software
Goodwill [Roll Forward]
Balance at September 30, 2016	69,047
Foreign currency translation adjustment	(648)
Balance at December 31, 2016	$ 68,399