XML 14 R1.htm IDEA: XBRL DOCUMENT v3.20.2
Cover - USD ($)
$ in Thousands
 12 Months Ended
Sep. 30, 2020
Nov. 30, 2020
Mar. 31, 2020
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Transition Report false    
Entity File Number 0-23333    
Entity Registrant Name TIMBERLAND BANCORP, INC.    
Entity Incorporation, State or Country Code WA    
Entity Tax Identification Number 91-1863696    
Entity Address, State or Province WA    
Entity Address, City or Town Hoquiam,    
Entity Address, Address Line One 624 Simpson Avenue,    
Entity Address, Postal Zip Code 98550    
Local Phone Number 533-4747    
City Area Code (360)    
Title of 12(b) Security Common stock, $.01 par value    
Trading Symbol TSBK    
Security Exchange Name NASDAQ    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Shell Company false    
Entity Common Stock, Shares Outstanding   8,315,993  
Entity Public Float     $ 151,980
Documents Incorporated by Reference
DOCUMENTS INCORPORATED BY REFERENCE
1.   Portions of Definitive Proxy Statement for the 2021 Annual Meeting of Shareholders (Part III).
    
Entity Central Index Key 0001046050    
Current Fiscal Year End Date --09-30    
Entity Filer Category Non-accelerated Filer    
Document Period End Date Sep. 30, 2020    
Document Fiscal Year Focus 2020    
Document Fiscal Period Focus FY    
Amendment Flag false    
Entity Small Business true    
Entity Emerging Growth Company false