Goodwill - Summary of Changes to Goodwill (Details) - USD ($)	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Goodwill [Line Items]
Accumulated goodwill impairment loss	$ 0
Goodwill [Roll Forward]
Beginning Balance	782,752,000	$ 773,327,000
Foreign currency translation adjustment	588,000	9,425,000
Ending Balance	783,340,000	782,752,000
Scores
Goodwill [Roll Forward]
Beginning Balance	146,648,000	146,648,000
Foreign currency translation adjustment	0	0
Ending Balance	146,648,000	146,648,000
Software
Goodwill [Roll Forward]
Beginning Balance	636,104,000	626,679,000
Foreign currency translation adjustment	588,000	9,425,000
Ending Balance	$ 636,692,000	$ 636,104,000