| Document and Entity Information | Jan. 26, 2022 |
| Document and Entity Information [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jan. 26, 2022 |
| Current Fiscal Year End Date | --12-31 |
| Entity Registrant Name | LAKE SHORE BANCORP, inc. |
| Entity Incorporation, State or Country Code | X1 |
| Entity File Number | 000-51821 |
| Entity Tax Identification Number | 20-4729288 |
| Entity Address, Address Line One | 31 East Fourth Street |
| Entity Address, City or Town | Dunkirk |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 14048 |
| City Area Code | 716 |
| Local Phone Number | 366-4070 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common stock, par value $0.01 per share |
| Trading Symbol | LSBK |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001341318 |
