Loans and Allowance for Credit Losses - Narrative (Details) $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($) category	Sep. 30, 2023 loan	Sep. 30, 2023 property	Dec. 31, 2022 USD ($)
Financing Receivable, Impaired [Line Items]
Foreclosed properties held	$ 0.9
Number of points in internal risk rating system | category	9
Number of categories in internal risk rating system considered as not criticized | category	6
Commercial relationship credit review threshold amount	$ 1.0
Commercial relationship credit review threshold amount, independent external review	$ 3.0
Past due period before loans placed in non-accrual status	90 days
Recent loan payment history before removal from non-accrual status	6 months
Impaired loans, related reserves	$ 0.0			$ 0.0
Liability for unfunded commitments	1.4			$ 0.5
Residential real estate
Financing Receivable, Impaired [Line Items]
Foreclosed properties held	0.8
Number foreclosed properties held		2,000,000	1
Investment in loans in the process of foreclosure	0.2
Residential real estate | Other Loan Relationships
Financing Receivable, Impaired [Line Items]
Foreclosed properties held	$ 0.1
Total commercial
Financing Receivable, Impaired [Line Items]
Number foreclosed properties held | loan		2