Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Total revenues	$ 322,361	$ 312,414
Revenue from Contract with Customer Benchmark [Member] | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	100.00%	100.00%
Revenue from Contract with Customer Benchmark [Member] | Geographic Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	100.00%	100.00%
Revenue from Contract with Customer Benchmark [Member] | Customer Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration Risk, Number of Customers	2	2
Revenue from Contract with Customer Benchmark [Member] | Customer Concentration Risk | TransUnion, Equifax and Experian customers
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	38.00%	34.00%
On-premises and SaaS software
Disaggregation of Revenue [Line Items]
Total revenues	$ 126,338	$ 126,455
On-premises and SaaS software | Revenue from Contract with Customer Benchmark [Member] | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	100.00%	100.00%
On-premises and SaaS software | Revenue from Contract with Customer Benchmark [Member] | Product Concentration Risk | Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	6.00%	10.00%
On-premises and SaaS software | Revenue from Contract with Customer Benchmark [Member] | Product Concentration Risk | Transferred over Time
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	94.00%	90.00%
On-Premises | Revenue from Contract with Customer Benchmark [Member] | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	45.00%	53.00%
SaaS Products | Revenue from Contract with Customer Benchmark [Member] | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	55.00%	47.00%
Platform software | Revenue from Contract with Customer Benchmark [Member] | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	17.00%	11.00%
Non-platform software | Revenue from Contract with Customer Benchmark [Member] | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	83.00%	89.00%
Americas
Disaggregation of Revenue [Line Items]
Total revenues	$ 264,897	$ 248,737
Americas | Revenue from Contract with Customer Benchmark [Member] | Geographic Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	82.00%	79.00%
EMEA [Member]
Disaggregation of Revenue [Line Items]
Total revenues	$ 38,891	$ 45,391
EMEA [Member] | Revenue from Contract with Customer Benchmark [Member] | Geographic Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	12.00%	15.00%
Asia Pacific [Member]
Disaggregation of Revenue [Line Items]
Total revenues	$ 18,573	$ 18,286
Asia Pacific [Member] | Revenue from Contract with Customer Benchmark [Member] | Geographic Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	6.00%	6.00%
Scores
Disaggregation of Revenue [Line Items]
Total revenues	$ 169,487	$ 144,651
Scores | Revenue from Contract with Customer Benchmark [Member] | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	100.00%	100.00%
Scores | Business to business Scores
Disaggregation of Revenue [Line Items]
Total revenues	$ 112,968	$ 100,144
Scores | Business to business Scores | Revenue from Contract with Customer Benchmark [Member] | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	67.00%	69.00%
Scores | Business to consumer Scores
Disaggregation of Revenue [Line Items]
Total revenues	$ 56,519	$ 44,507
Scores | Business to consumer Scores | Revenue from Contract with Customer Benchmark [Member] | Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	33.00%	31.00%
Scores | Operating Segments
Disaggregation of Revenue [Line Items]
Total revenues	$ 169,487	$ 144,651
Scores | Operating Segments | On-premises and SaaS software
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Scores | Americas
Disaggregation of Revenue [Line Items]
Total revenues	165,712	140,713
Scores | EMEA [Member]
Disaggregation of Revenue [Line Items]
Total revenues	1,493	1,713
Scores | Asia Pacific [Member]
Disaggregation of Revenue [Line Items]
Total revenues	2,282	2,225
Software
Disaggregation of Revenue [Line Items]
Total revenues	152,874	167,763
Software | On-premises and SaaS software
Disaggregation of Revenue [Line Items]
Total revenues	126,338	126,455
Software | On-premises and SaaS software | Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Total revenues	7,159	12,894
Software | On-premises and SaaS software | Transferred over Time
Disaggregation of Revenue [Line Items]
Total revenues	119,179	113,561
Software | On-Premises
Disaggregation of Revenue [Line Items]
Total revenues	57,295	66,482
Software | SaaS Products
Disaggregation of Revenue [Line Items]
Total revenues	69,043	59,973
Software | Platform software
Disaggregation of Revenue [Line Items]
Total revenues	22,072	14,125
Software | Non-platform software
Disaggregation of Revenue [Line Items]
Total revenues	104,266	112,330
Software | Operating Segments
Disaggregation of Revenue [Line Items]
Total revenues	152,874	167,763
Software | Operating Segments | On-premises and SaaS software
Disaggregation of Revenue [Line Items]
Total revenues	126,338	126,455
Software | Americas
Disaggregation of Revenue [Line Items]
Total revenues	99,185	108,024
Software | EMEA [Member]
Disaggregation of Revenue [Line Items]
Total revenues	37,398	43,678
Software | Asia Pacific [Member]
Disaggregation of Revenue [Line Items]
Total revenues	$ 16,291	$ 16,061