Loans and Allowance for Credit Losses - Loan portfolio aging analysis (Details)	12 Months Ended
	Jun. 30, 2024 USD ($) loan	Jun. 30, 2023 USD ($) loan
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	$ 3,850,035,000	$ 3,619,197,000
Greater than 90 Days Past Due and Accruing		109,000
Financial Asset, Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	9,201,000	10,741,000
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	3,128,000	4,212,000
60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	2,621,000	2,767,000
Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	$ 3,452,000	$ 3,762,000
Number of PCD loans greater than 90 days past due | loan	1	0
Purchased credit-impaired loans	$ 560,000	$ 0
Financial Asset, Not Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	3,840,834,000	3,608,456,000
Residential Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,185,692,000	1,133,417,000
Greater than 90 Days Past Due and Accruing		109,000
Residential Portfolio Segment [Member] | Financial Asset, Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	2,846,000	2,868,000
Residential Portfolio Segment [Member] | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	520,000	1,984,000
Residential Portfolio Segment [Member] | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,848,000	401,000
Residential Portfolio Segment [Member] | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	478,000	483,000
Residential Portfolio Segment [Member] | Financial Asset, Not Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,182,846,000	1,130,549,000
Construction Real Estate
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	229,088,000	190,856,000
Construction Real Estate | Financial Asset, Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	589,000	1,452,000
Construction Real Estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	213,000	443,000
Construction Real Estate | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	376,000	311,000
Construction Real Estate | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable		698,000
Construction Real Estate | Financial Asset, Not Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	228,499,000	189,404,000
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,622,365,000	1,562,379,000
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	2,138,000	4,050,000
Commercial Real Estate Portfolio Segment [Member] | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,042,000	616,000
Commercial Real Estate Portfolio Segment [Member] | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,000	1,854,000
Commercial Real Estate Portfolio Segment [Member] | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,095,000	1,580,000
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Not Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,620,227,000	1,558,329,000
Consumer Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	144,598,000	133,515,000
Consumer Portfolio Segment [Member] | Financial Asset, Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	917,000	792,000
Consumer Portfolio Segment [Member] | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	476,000	456,000
Consumer Portfolio Segment [Member] | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	311,000	124,000
Consumer Portfolio Segment [Member] | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	130,000	212,000
Consumer Portfolio Segment [Member] | Financial Asset, Not Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	143,681,000	132,723,000
Commercial Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	668,292,000	599,030,000
Commercial Portfolio Segment [Member] | Financial Asset, Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	2,711,000	1,579,000
Commercial Portfolio Segment [Member] | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	877,000	713,000
Commercial Portfolio Segment [Member] | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	85,000	77,000
Commercial Portfolio Segment [Member] | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,749,000	789,000
Commercial Portfolio Segment [Member] | Financial Asset, Not Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	$ 665,581,000	$ 597,451,000