Disclosures about Fair Value of Assets and Liabilities - Other Assets Measured at Fair Value on Nonrecurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Significant Unobservable Inputs (Level 3) | Collateral dependent loans
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fair Value	$ 18,848	$ 13,123
Significant Unobservable Inputs (Level 3) | Mortgage servicing rights
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fair Value	14,863	12,472
Fair Value, Nonrecurring | Collateral dependent loans
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fair Value	18,848	13,123
Fair Value, Nonrecurring | Mortgage servicing rights
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fair Value	14,863	12,472
Fair Value, Nonrecurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Collateral dependent loans
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fair Value	0	0
Fair Value, Nonrecurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Mortgage servicing rights
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fair Value	0	0
Fair Value, Nonrecurring | Significant Other Observable Inputs (Level 2) | Collateral dependent loans
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fair Value	0	0
Fair Value, Nonrecurring | Significant Other Observable Inputs (Level 2) | Mortgage servicing rights
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fair Value	0	0
Fair Value, Nonrecurring | Significant Unobservable Inputs (Level 3) | Collateral dependent loans
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fair Value	18,848	13,123
Fair Value, Nonrecurring | Significant Unobservable Inputs (Level 3) | Mortgage servicing rights
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fair Value	$ 14,863	$ 12,472