Employee Benefit Plans (Narrative) (Details)	1 Months Ended			3 Months Ended		9 Months Ended
	Jan. 31, 2021 USD ($) employee	Jan. 31, 2020 USD ($) employee	Jan. 31, 2019 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Discretionary contribution as percentage of employee's base pay						15.00%
Defined contribution plan consecutive years of service to be completed by participant						2 years
Period to refrain from engaging in competitive employment following separation from service						3 years
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Period of employment used to determine benefits						5 years
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 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 their (a) ages, at their closest birthday plus (b) 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 are managed through discretionary contributions to the First United Corporation 401(k) Profit Sharing Plan (the “401(k) Plan”).
Employer discretionary contribution						$ 0	$ 1,000,000.0
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer discretionary contribution	$ 101,257	$ 126,058	$ 123,179	$ 12,657
Defined contribution plan, number of employees | employee	3	4
Vesting period of employer discretionary contribution			2 years			2 years
Defined benefit plan participants compensation expense						$ 37,971
SERP [Member] | Four Participants [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan participants compensation expense				$ 15,757	$ 15,757	$ 47,271	$ 47,271