| Document and Entity Information | Feb. 07, 2024 |
| Document and Entity Information [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Feb. 07, 2024 |
| Entity File Number | 001-38991 |
| Entity Registrant Name | Pioneer Bancorp, Inc./MD |
| Entity Incorporation, State or Country Code | MD |
| Entity Tax Identification Number | 83-4274253 |
| Entity Address State Or Province | NY |
| Entity Address, Address Line One | 652 Albany Shaker Road |
| Entity Address, City or Town | Albany |
| Entity Address, Postal Zip Code | 12211 |
| City Area Code | 518 |
| Local Phone Number | 730-3025 |
| Title of 12(b) Security | Common Stock, par value $0.01 |
| Trading Symbol | PBFS |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Entity Central Index Key | 0001769663 |
| Amendment Flag | false |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
