Employee Benefit Plans (Narrative) (Details)		1 Months Ended		12 Months Ended
	Jan. 31, 2019 USD ($)	Jan. 31, 2021 USD ($) employee	Jan. 31, 2020 USD ($) employee	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Jan. 31, 2018 employee
Defined Benefit Plan Disclosure [Line Items]
Discretionary contribution as percentage of employee's base pay				15.00%
Defined benefit plan participants compensation expense				$ 1,100,000	$ 1,200,000
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan modification description				Effective April 30, 2010, the Pension Plan was amended, resulting in a “soft freeze”, the effect of which prohibits new entrants into the Pension Plan and ceases crediting of additional years of service, after that date. Effective January 1, 2013, the Pension Plan was amended to unfreeze it for those employees for whom the sum of (i) their ages, at their closest birthday, plus (ii) years of service for vesting purposes equals 80 or greater. The “soft freeze” continues to apply to all other plan participants. Pension benefits for these participants will be managed through discretionary contributions to the First United Corporation 401(k) Profit Sharing Plan (the “401(k) Plan”).
Defined Benefit Plan, Accumulated Benefit Obligation				$ 54,000,000.0	48,900,000
Period for average return on pension portfolio assets				25 years
Average return on pension portfolio assets				7.05%
Expected long-term return on pension portfolio assets				7.00%
Defined benefit plan, contribution by employer				$ 1,000,000	2,000,000
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer discretionary contribution	$ 123,179
Defined contribution plan, number of employees | employee						4
Vesting period of employer discretionary contribution				2 years
Defined benefit plan participants compensation expense				$ 48,027	75,175
Defined Benefit Plan, Accumulated Benefit Obligation				8,700,000	7,700,000
Defined benefit plan, contribution by employer				266,000	$ 283,000
SERP [Member] | Subsequent Event [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer discretionary contribution		$ 101,257
Defined contribution plan, number of employees | employee		3
Vesting period of employer discretionary contribution		2 years
SERP [Member] | Four Participants [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer discretionary contribution			$ 126,058
Defined contribution plan, number of employees | employee			4
Defined benefit plan participants compensation expense				$ 63,029