Goodwill and Intangible Assets - Summary of Changes to Goodwill (Detail) $ in Thousands	3 Months Ended
	Dec. 31, 2019 USD ($)
Goodwill [Roll Forward]
Balance at September 30, 2019	$ 803,542
Foreign currency translation adjustment	9,308
Balance at December 31, 2019	812,850
Applications
Goodwill [Roll Forward]
Balance at September 30, 2019	588,614
Foreign currency translation adjustment	8,292
Balance at December 31, 2019	596,906
Scores
Goodwill [Roll Forward]
Balance at September 30, 2019	146,648
Foreign currency translation adjustment	0
Balance at December 31, 2019	146,648
Decision Management Software
Goodwill [Roll Forward]
Balance at September 30, 2019	68,280
Foreign currency translation adjustment	1,016
Balance at December 31, 2019	$ 69,296