Commitments and Contingencies - Narrative (Details) $ in Thousands	Sep. 30, 2020 USD ($)
Derecho Storm, 2020 [Member]
Concentration Risk [Line Items]
Short-term loan modification, primarily 1 to 4 family non-owner occupied, multifamily, and commercial real estate loans	$ 15,380
State and political subdivisions [Member]
Concentration Risk [Line Items]
Investment in securities issued by state and political subdivisions within the state of Iowa	$ 81,420

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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