Available for Sale Securities - Investments Pledged as Collateral to Secure Public Deposits and Securities Sold Under Agreements to Repurchase (Details) - Pledged as collateral - Public deposits - USD ($) $ in Millions	Jun. 30, 2025	Jun. 30, 2024
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral	$ 294.3	$ 265.5
MBS
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral	151.6	137.0
CMOs
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral	109.8	103.5
Obligations of states and political subdivisions
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral	29.7	20.8
Other securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Carrying value of investment and MBS pledged as collateral to secure public deposits and securities sold under agreements to repurchase	$ 3.3	$ 4.3