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	Mar. 31, 2024	Jun. 30, 2023
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral	$ 268.0	$ 253.9
Asset backed securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral	137.3	129.2
Collateralized Mortgage Obligations
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral	107.5	94.8
US States and Political Subdivisions Debt Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged as collateral	18.7	26.5
Other securities [Member]
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	$ 4.5	$ 3.4