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, 2024	Dec. 31, 2023
Interest Rate Swap Agreements
Offsetting Assets And Liabilities [Line Items]
Fair value of investment securities pledged	$ 51.0	$ 39.2
Private Institutions
Offsetting Assets And Liabilities [Line Items]
Fair value of investment securities pledged	109.9	167.3
Government Entities
Offsetting Assets And Liabilities [Line Items]
Fair value of investment securities pledged	$ 0.7	$ 0.7