v3.25.2
Document And Entity Information - shares
9 Months Ended
Jun. 30, 2025
Aug. 05, 2025
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2025  
Document Transition Report false  
Entity File Number 001-33390  
Entity Registrant Name TFS FINANCIAL CORPORATION  
Entity Incorporation, State or Country Code X1  
Entity Tax Identification Number 52-2054948  
Entity Address, Address Line One 7007 Broadway Avenue  
Entity Address, City or Town Cleveland,  
Entity Address, State or Province OH  
Entity Address, Postal Zip Code 44105  
City Area Code 216  
Local Phone Number 441-6000  
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  
Title of 12(b) Security Common Stock, par value $0.01 per share  
Trading Symbol TFSL  
Security Exchange Name NASDAQ  
Entity Common Stock, Shares Outstanding   280,688,024
Entity Central Index Key 0001381668  
Current Fiscal Year End Date --09-30  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q3  
Amendment Flag false