Segment Information - Disaggregation of revenues (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Revenues	$ 313,731	$ 314,249	$ 920,206	$ 854,739
North America [Member]
Disaggregation of Revenue [Line Items]
Revenues	230,489	213,868	664,895	595,031
Latin America [Member]
Disaggregation of Revenue [Line Items]
Revenues	16,808	13,304	49,150	48,661
EMEA [Member]
Disaggregation of Revenue [Line Items]
Revenues	44,107	65,042	135,605	147,145
Asia Pacific [Member]
Disaggregation of Revenue [Line Items]
Revenues	22,327	22,035	70,556	63,902
On-Premises Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	105,556	129,811	320,401	350,051
SaaS Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	76,625	69,292	223,969	199,456
Scores Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	131,550	115,146	375,836	305,232
Scores
Disaggregation of Revenue [Line Items]
Revenues	131,550	115,146	375,836	305,232
Scores | North America [Member]
Disaggregation of Revenue [Line Items]
Revenues	128,686	110,728	362,132	293,292
Scores | Latin America [Member]
Disaggregation of Revenue [Line Items]
Revenues	113	768	3,016	2,650
Scores | EMEA [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,505	2,191	4,763	5,197
Scores | Asia Pacific [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,246	1,459	5,925	4,093
Scores | On-Premises Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Scores | SaaS Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Scores | Scores Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	131,550	115,146	375,836	305,232
Decision Management Software
Disaggregation of Revenue [Line Items]
Revenues	40,721	33,466	110,453	94,396
Decision Management Software | North America [Member]
Disaggregation of Revenue [Line Items]
Revenues	23,164	14,930	59,758	45,354
Decision Management Software | Latin America [Member]
Disaggregation of Revenue [Line Items]
Revenues	4,626	5,448	14,876	14,000
Decision Management Software | EMEA [Member]
Disaggregation of Revenue [Line Items]
Revenues	8,427	8,680	22,612	21,977
Decision Management Software | Asia Pacific [Member]
Disaggregation of Revenue [Line Items]
Revenues	4,504	4,408	13,207	13,065
Decision Management Software | On-Premises Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	29,063	27,138	81,589	76,472
Decision Management Software | SaaS Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	11,658	6,328	28,864	17,924
Decision Management Software | Scores Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Applications
Disaggregation of Revenue [Line Items]
Revenues	141,460	165,637	433,917	455,111
Applications | North America [Member]
Disaggregation of Revenue [Line Items]
Revenues	78,639	88,210	243,005	256,385
Applications | Latin America [Member]
Disaggregation of Revenue [Line Items]
Revenues	12,069	7,088	31,258	32,011
Applications | EMEA [Member]
Disaggregation of Revenue [Line Items]
Revenues	34,175	54,171	108,230	119,971
Applications | Asia Pacific [Member]
Disaggregation of Revenue [Line Items]
Revenues	16,577	16,168	51,424	46,744
Applications | On-Premises Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	76,493	102,673	238,812	273,579
Applications | SaaS Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	64,967	62,964	195,105	181,532
Applications | Scores Products [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 0	$ 0	$ 0	$ 0
Revenue from Contract with Customer Benchmark [Member]
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Revenue from Contract with Customer Benchmark [Member] | Scores
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	42.00%	37.00%	41.00%	36.00%
Revenue from Contract with Customer Benchmark [Member] | Decision Management Software
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	13.00%	10.00%	12.00%	11.00%
Revenue from Contract with Customer Benchmark [Member] | Applications
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage	45.00%	53.00%	47.00%	53.00%