| Document and Entity Information | May 16, 2024 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | May 16, 2024 |
| Entity File Number | 001-39883 |
| Entity Registrant Name | Generations Bancorp NY, Inc. |
| Entity Central Index Key | 0001823365 |
| Entity Incorporation, State or Country Code | MD |
| Entity Tax Identification Number | 85-3659943 |
| Entity Address, Address Line One | 20 East Bayard Street |
| Entity Address, City or Town | Seneca Falls |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 13148 |
| City Area Code | 315 |
| Local Phone Number | 568-5855 |
| Title of 12(b) Security | Common Stock, Par Value $0.01 Per Share |
| Trading Symbol | GBNY |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
