XML 12 R1.htm IDEA: XBRL DOCUMENT v3.21.2
Cover Page - shares
 6 Months Ended
Jun. 30, 2021
Aug. 02, 2021
Document Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2021  
Document Transition Report false  
Entity File Number 001-37468  
Entity Registrant Name AppFolio, Inc.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 26-0359894  
Entity Address, Address Line One 50 Castilian Drive  
Entity Address, City or Town Santa Barbara,  
Entity Address, State or Province CA  
Entity Address, Postal Zip Code 93117  
City Area Code 805  
Local Phone Number 364-6093  
Title of 12(b) Security Class A Common Stock, $0.0001 par value  
Trading Symbol APPF  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Central Index Key 0001433195  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2021  
Document Fiscal Period Focus Q2  
Amendment Flag false  
Class A common stock    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   18,991,205
Class B common stock    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   15,620,784