Securities Sold Under Agreements to Repurchase - Schedule of Assets and Liabilities Subject to an Enforceable Master Netting Arrangement or Repurchase Agreements (Parenthetical) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Interest Rate Swap Agreements
Offsetting Assets And Liabilities [Line Items]
Fair value of investment securities pledged	$ 3.5	$ 34.8
Private Institutions
Offsetting Assets And Liabilities [Line Items]
Fair value of investment securities pledged	763.3	755.9
Government Entities
Offsetting Assets And Liabilities [Line Items]
Fair value of investment securities pledged	$ 0.8	$ 0.8