v3.19.3.a.u2
Cover - shares
3 Months Ended
Dec. 31, 2019
Jan. 17, 2020
Cover page.    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Dec. 31, 2019  
Document Transition Report false  
Entity File Number 1-11689  
Entity Registrant Name Fair Isaac Corp  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 94-1499887  
Entity Address, Address Line One 181 Metro Drive, Suite 700  
Entity Address, Postal Zip Code 95110-1346  
Entity Address, City or Town San Jose  
Entity Address, State or Province CA  
City Area Code 408  
Local Phone Number 535-1500  
Title of 12(b) Security Common Stock, $0.01 par value per share  
Trading Symbol FICO  
Security Exchange Name NYSE  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   29,148,054
Entity Central Index Key 0000814547  
Current Fiscal Year End Date --09-30  
Document Fiscal Year Focus 2020  
Document Fiscal Period Focus Q1  
Amendment Flag false