Loans and Allowance for Credit Losses - Loan portfolio aging analysis (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Jun. 30, 2021
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	$ 2,391,423	$ 2,237,091
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,495	1,238
60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,117	1,369
Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	734	1,211
Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	3,346	3,818
Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	2,388,077	2,233,273
Residential Real Estate
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	809,196	721,216
Residential Real Estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	601	312
Residential Real Estate | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	520	364
Residential Real Estate | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	638	613
Residential Real Estate | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,759	1,289
Residential Real Estate | Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	807,437	719,927
Construction Real Estate
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	147,617	134,284
Construction Real Estate | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable		30
Construction Real Estate | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable		30
Construction Real Estate | Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	147,617	134,254
Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	963,299	889,793
Commercial Real Estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	397	363
Commercial Real Estate | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	471
Commercial Real Estate | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable		374
Commercial Real Estate | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	868	737
Commercial Real Estate | Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	962,431	889,056
Consumer loans
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	81,049	77,674
Consumer loans | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	326	195
Consumer loans | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	120	66
Consumer loans | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	69	84
Consumer loans | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	515	345
Consumer loans | Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	80,534	77,329
Commercial loans
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	390,262	414,124
Commercial loans | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	171	368
Commercial loans | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	6	939
Commercial loans | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	27	110
Commercial loans | Total Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	204	1,417
Commercial loans | Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	$ 390,058	$ 412,707