Loans and Allowance for Credit Losses on Loans - Amortized Cost Basis of Collateral-dependent Loans (Details) $ in Thousands	Dec. 31, 2020 USD ($)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Collateral dependent loans	$ 1,974
Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Collateral dependent loans	29
Business Assets
Financing Receivable, Recorded Investment, Past Due [Line Items]
Collateral dependent loans	1,815
Uncollateralized
Financing Receivable, Recorded Investment, Past Due [Line Items]
Collateral dependent loans	130
Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Collateral dependent loans	1,974
Commercial | Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Collateral dependent loans	29
Commercial | Business Assets
Financing Receivable, Recorded Investment, Past Due [Line Items]
Collateral dependent loans	1,815
Commercial | Uncollateralized
Financing Receivable, Recorded Investment, Past Due [Line Items]
Collateral dependent loans	$ 130