Segment Information - Additional Information (Detail)	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Segment Reporting Information [Line Items]
Concentration of risk percentage	100.00%	100.00%	100.00%
Credit Concentration Risk
Segment Reporting Information [Line Items]
Concentration of risk percentage	18.00%	18.00%	20.00%
Sales Revenue, Services, Net | Applications
Segment Reporting Information [Line Items]
Concentration of risk percentage	63.00%	62.00%	61.00%
Sales Revenue, Services, Net | Applications | Fraud Solutions
Segment Reporting Information [Line Items]
Concentration of risk percentage	25.00%	23.00%	20.00%
Sales Revenue, Services, Net | Applications | Customer Management Solutions
Segment Reporting Information [Line Items]
Concentration of risk percentage	13.00%	13.00%	14.00%
Sales Revenue, Services, Net | Applications | Marketing Solutions
Segment Reporting Information [Line Items]
Concentration of risk percentage	9.00%	10.00%	11.00%