v2.4.0.6
Document and Entity Information
6 Months Ended
Mar. 31, 2012
Apr. 23, 2012
Document Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Mar. 31, 2012  
Document Fiscal Year Focus 2012  
Document Fiscal Period Focus Q2  
Trading Symbol FICO  
Entity Registrant Name Fair Isaac Corporation  
Entity Central Index Key 0000814547  
Current Fiscal Year End Date --09-30  
Entity Filer Category Large Accelerated Filer  
Entity Common Stock, Shares Outstanding   34,284,474