Employee Benefit Plans (Narrative) (Details) - USD ($)
 1 Months Ended 3 Months Ended 9 Months Ended
Jan. 31, 2020
Jan. 31, 2019
Jan. 31, 2018
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
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  
Defined benefit plan participants compensation expense       $ 15,757   $ 47,272  
Period to refrain from engaging in competitive employment following separation from service           3 years  
Four Employees [Member]              
Defined Benefit Plan Disclosure [Line Items]              
Employer discretionary contribution $ 126,058 $ 123,179 $ 119,252        
Vesting period of employer discretionary contribution           2 years  
Defined benefit plan participants compensation expense       $ 12,007 $ 14,906 $ 36,020 $ 44,719
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           $ 1,000,000.0