Segment Information - Summary of Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Segment revenues:
Total revenues	$ 344,870	$ 322,361
Segment operating expense	(204,531)	(206,775)
Operating income	140,339	115,586
Unallocated share-based compensation expense	(29,702)	(29,878)
Unallocated amortization expense	(275)	(544)
Unallocated interest expense	(22,800)	(12,195)
Unallocated other income, net	364	1,429
Income before income taxes	117,903	104,820
Depreciation expense	3,147	4,098
Operating Segments
Segment revenues:
Segment operating expense	(176,495)	(176,353)
Operating income	168,375	146,008
Unallocated Corporate Expenses
Segment revenues:
Segment operating expense	(34,082)	(37,152)
Operating income	(34,082)	(37,152)
Depreciation expense	22	29
Scores
Segment revenues:
Total revenues	177,988	169,487
Scores | Operating Segments
Segment revenues:
Total revenues	177,988	169,487
Segment operating expense	(21,296)	(21,164)
Operating income	156,692	148,323
Depreciation expense	151	192
Software
Segment revenues:
Total revenues	166,882	152,874
Software | Operating Segments
Segment revenues:
Total revenues	166,882	152,874
Segment operating expense	(121,117)	(118,037)
Operating income	45,765	34,837
Depreciation expense	2,974	3,877
Professional services
Segment revenues:
Total revenues	22,322	26,536
Professional services | Scores | Operating Segments
Segment revenues:
Total revenues	0	0
Professional services | Software | Operating Segments
Segment revenues:
Total revenues	22,322	26,536
On-premises and SaaS software
Segment revenues:
Total revenues	144,560	126,338
On-premises and SaaS software | Scores | Operating Segments
Segment revenues:
Total revenues	0	0
On-premises and SaaS software | Software
Segment revenues:
Total revenues	144,560	126,338
On-premises and SaaS software | Software | Operating Segments
Segment revenues:
Total revenues	144,560	126,338
Scores
Segment revenues:
Total revenues	177,988	169,487
Scores | Scores | Operating Segments
Segment revenues:
Total revenues	177,988	169,487
Scores | Software | Operating Segments
Segment revenues:
Total revenues	$ 0	$ 0