| Document and Entity Information | Apr. 27, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Apr. 27, 2021 |
| Entity Registrant Name | QNB Corp. |
| Entity Central Index Key | 0000750558 |
| Entity Emerging Growth Company | false |
| Entity File Number | 0-17706 |
| Entity Incorporation, State or Country Code | PA |
| Entity Tax Identification Number | 23-2318082 |
| Entity Address, Address Line One | 15 North Third Street |
| Entity Address, Address Line Two | P.O. Box 9005 |
| Entity Address, City or Town | Quakertown |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 18951-9005 |
| City Area Code | 215 |
| Local Phone Number | 538-5600 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock |
| Trading Symbol | QNBC |
| Security Exchange Name | NONE |
