| Cover | Apr. 27, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Apr. 27, 2021 |
| Entity File Number | 000-17077 |
| Entity Registrant Name | PENNS WOODS BANCORP, INC. |
| Entity Central Index Key | 0000716605 |
| Entity Tax Identification Number | 23-2226454 |
| Entity Incorporation, State or Country Code | PA |
| Entity Address, Address Line One | 300 Market Street |
| Entity Address, Address Line Two | P.O. Box 967 |
| Entity Address, City or Town | Williamsport |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 17703-0967 |
| City Area Code | 570 |
| Local Phone Number | 322-1111 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $5.55 par value |
| Trading Symbol | PWOD |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
