| Cover | Oct. 26, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Oct. 26, 2021 |
| Entity File Number | 0-14237 |
| Entity Registrant Name | First United Corporation |
| Entity Central Index Key | 0000763907 |
| Entity Tax Identification Number | 52-1380770 |
| Entity Incorporation, State or Country Code | MD |
| Entity Address, Address Line One | 19 South Second Street |
| Entity Address, City or Town | Oakland |
| Entity Address, State or Province | MD |
| Entity Address, Postal Zip Code | 21550 |
| City Area Code | 301 |
| Local Phone Number | 334-9471 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | FUNC |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
