Loans and Allowance for Credit Losses - Loan portfolio aging analysis (Details) - USD ($)	9 Months Ended	12 Months Ended
	Mar. 31, 2022	Jun. 30, 2021
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	$ 2,613,337,000	$ 2,237,091,000
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	2,957,000	1,238,000
60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	470,000	1,369,000
Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	999,000	1,211,000
PCD loans that were greater than 90 days past due	0	0
Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	4,426,000	3,818,000
Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	2,608,911,000	2,233,273,000
Residential Real Estate
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	894,007,000	721,216,000
Residential Real Estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,573,000	312,000
Residential Real Estate | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	105,000	364,000
Residential Real Estate | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	563,000	613,000
Residential Real Estate | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	2,241,000	1,289,000
Residential Real Estate | Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	891,766,000	719,927,000
Construction Real Estate
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	131,465,000	134,284,000
Construction Real Estate | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable		30,000
Construction Real Estate | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable		30,000
Construction Real Estate | Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	131,465,000	134,254,000
Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,091,914,000	889,793,000
Commercial Real Estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	638,000	363,000
Commercial Real Estate | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	236,000
Commercial Real Estate | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	400,000	374,000
Commercial Real Estate | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,274,000	737,000
Commercial Real Estate | Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,090,640,000	889,056,000
Consumer loans
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	86,230,000	77,674,000
Consumer loans | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	478,000	195,000
Consumer loans | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	80,000	66,000
Consumer loans | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	7,000	84,000
Consumer loans | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	565,000	345,000
Consumer loans | Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	85,665,000	77,329,000
Commercial loans
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	409,721,000	414,124,000
Commercial loans | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	268,000	368,000
Commercial loans | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	49,000	939,000
Commercial loans | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	29,000	110,000
Commercial loans | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	346,000	1,417,000
Commercial loans | Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	$ 409,375,000	$ 412,707,000