| Document and Entity Information | Jan. 27, 2022 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jan. 27, 2022 |
| Entity Registrant Name | RIVERVIEW BANCORP, INC. |
| Entity Incorporation, State or Country Code | WA |
| Entity File Number | 000-22957 |
| Entity Tax Identification Number | 91-1838969 |
| Entity Address, Address Line One | 900 Washington Street |
| Entity Address, Address Line Two | Suite 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 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001041368 |
| Title of 12(b) Security | Common Stock, Par Value $0.01 per share |
| Trading Symbol | RVSB |
| Security Exchange Name | NASDAQ |
