Organization and Nature of Business and Summary of Significant Accounting Policies (Branches) (Details)	Dec. 31, 2021 Bank_branches
Des Moines, Iowa metropolitan area branches, excluding main [Member]
Number of bank branches by location [Line Items]
Number of bank branches	6
Coralville, Iowa [Member]
Number of bank branches by location [Line Items]
Number of bank branches	1
Southern Minnesota [Member]
Number of bank branches by location [Line Items]
Number of bank branches	4