Organization and Summary of Significant Accounting Policies - Goodwill and Intangible Assets (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Mar. 31, 2024	Jun. 30, 2023
Finite-Lived Intangible Assets [Line Items]
Impairment loss on goodwill	$ 0.0	$ 0.0
Core deposit intangible assets, amortization method	using the straight line method
Impairment of intangible assets	$ 0.0	0.0
Core Deposits
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	39.1	39.1
Intangibles assets, accumulated amortization	16.9	14.0
Remainder of fiscal 2024	1.0
2025	3.5
2026	3.0
2027	2.7
2028	2.7
Thereafter	11.5
Other identifiable intangibles
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	6.4	6.4
Intangibles assets, accumulated amortization	4.1	3.9
Mortgage and SBA servicing rights
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net	$ 2.8	$ 2.9
Minimum | Core Deposits
Finite-Lived Intangible Assets [Line Items]
Intangible assets, amortization period	5 years
Maximum | Core Deposits
Finite-Lived Intangible Assets [Line Items]
Intangible assets, amortization period	10 years