v3.26.1
Document and Entity Information - USD ($)
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Jun. 12, 2026
Sep. 30, 2025
Document and Entity Information:        
Document Type 10-K      
Document Annual Report true      
Document Period End Date Mar. 31, 2026      
Document Transition Report false      
Securities Act File Number 000-22957      
Entity Registrant Name RIVERVIEW BANCORP INC      
Entity Incorporation, State or Country Code WA      
Entity Tax Identification Number 91-1838969      
Entity Address, Address Line One 900 Washington St.      
Entity Address, Address Line Two Ste. 900      
Entity Address, City or Town Vancouver      
Entity Address, State or Province WA      
Entity Address, Postal Zip Code 98660      
City Area Code 360      
Local Phone Number 693-6650      
Title of 12(b) Security Common Stock, Par Value $0.01 per share      
Trading Symbol RVSB      
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 Filer Category Non-accelerated Filer      
Entity Small Business true      
Entity Emerging Growth Company false      
ICFR Auditor Attestation Flag false      
Document Financial Statement Error Correction [Flag] false      
Entity Shell Company false      
Entity Public Float       $ 112,380,691
Entity Common Stock, Shares Outstanding     20,284,946  
Documents Incorporated by Reference [Text Block]

Portions of registrant’s Definitive Proxy Statement for the 2026 Annual Meeting of Stockholders (Part III), which will be filed with the U.S. Securities and Exchange Commission within 120 days after the end of the fiscal year to which this report relates.

      
Auditor Name Aprio, LLP Delap LLP    
Auditor Firm ID 926 116    
Auditor Location Lake Oswego, Oregon Lake Oswego, Oregon    
Entity Central Index Key 0001041368      
Current Fiscal Year End Date --03-31      
Document Fiscal Year Focus 2026      
Document Fiscal Period Focus FY      
Amendment Flag false