Loans and Allowance for Credit Losses - Loan portfolio aging analysis (Details)	Mar. 31, 2023 USD ($) loan	Jun. 30, 2022 USD ($)
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	$ 3,480,520,000	$ 2,719,843,000
Number of PCD loans greater than 90 days past due | loan	1
PCD loan greater than 90 days past due	$ 139,000	0
Current Loans, not past due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	3,473,138,000	2,715,257,000
Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	7,382,000	4,586,000
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	3,253,000	2,432,000
60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,008,000	732,000
Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	3,121,000	1,422,000
Residential Real Estate
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,120,970,000	904,160,000
Residential Real Estate | Current Loans, not past due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,118,021,000	901,694,000
Residential Real Estate | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	2,949,000	2,466,000
Residential Real Estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	2,110,000	1,402,000
Residential Real Estate | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	203,000
Residential Real Estate | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	636,000	1,064,000
Construction Real Estate
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	212,774,000	134,416,000
Construction Real Estate | Current Loans, not past due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	212,265,000	134,416,000
Construction Real Estate | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	509,000
Construction Real Estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	141,000
Construction Real Estate | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	368,000
Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,460,314,000	1,146,673,000
Commercial Real Estate | Current Loans, not past due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,458,261,000	1,145,354,000
Commercial Real Estate | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	2,053,000	1,319,000
Commercial Real Estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	281,000	416,000
Commercial Real Estate | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	97,000	615,000
Commercial Real Estate | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,675,000	288,000
Consumer loans
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	125,483,000	92,996,000
Consumer loans | Current Loans, not past due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	124,527,000	92,554,000
Consumer loans | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	956,000	442,000
Consumer loans | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	536,000	340,000
Consumer loans | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	244,000	45,000
Consumer loans | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	176,000	57,000
Commercial loans
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	560,979,000	441,598,000
Commercial loans | Current Loans, not past due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	560,064,000	441,239,000
Commercial loans | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	915,000	359,000
Commercial loans | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	185,000	274,000
Commercial loans | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	96,000	72,000
Commercial loans | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	$ 634,000	$ 13,000