Loans and Allowance for Credit Losses - Schedule of loan portfolio aging analysis (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Jun. 30, 2020
Financing Receivables Past Due
Financing Receivable Recorded Investment	$ 4,304	$ 6,393
Financing Receivables Past Due | Consumer Loan
Financing Receivable Recorded Investment	469	426
Financing Receivables Past Due | Commercial Loan
Financing Receivable Recorded Investment	520	2,122
Financing Receivables Past Due | Residential real estate loans
Financing Receivable Recorded Investment	1,575	1,804
Financing Receivables Past Due | Commercial Real Estate
Financing Receivable Recorded Investment	1,740	2,041
Loans Receivable
Financing Receivable Recorded Investment		2,171,463
Loans Receivable | Consumer Loan
Financing Receivable Recorded Investment	76,347	80,767
Loans Receivable | Commercial Loan
Financing Receivable Recorded Investment	421,825	468,448
Loans Receivable | Construction Real Estate
Financing Receivable Recorded Investment	122,742	107,472
Loans Receivable | Residential real estate loans
Financing Receivable Recorded Investment	655,800	627,357
Loans Receivable | Commercial Real Estate
Financing Receivable Recorded Investment	897,450	887,419
Total Loans
Financing Receivable Recorded Investment	2,174,164
Financial Asset, 30 to 59 Days Past Due
Financing Receivable Recorded Investment		1,686
Financial Asset, 30 to 59 Days Past Due | Consumer Loan
Financing Receivable Recorded Investment	322	180
Financial Asset, 30 to 59 Days Past Due | Commercial Loan
Financing Receivable Recorded Investment	333	93
Financial Asset, 30 to 59 Days Past Due | Residential real estate loans
Financing Receivable Recorded Investment	1,270	772
Financial Asset, 30 to 59 Days Past Due | Commercial Real Estate
Financing Receivable Recorded Investment	1,329	641
Financial Asset, 30 to 59 Days Past Due | Total Loans
Financing Receivable Recorded Investment	3,254
Financial Asset, 60 to 89 Days Past Due
Financing Receivable Recorded Investment		1,977
Financial Asset, 60 to 89 Days Past Due | Consumer Loan
Financing Receivable Recorded Investment	52	53
Financial Asset, 60 to 89 Days Past Due | Commercial Loan
Financing Receivable Recorded Investment	39	1,219
Financial Asset, 60 to 89 Days Past Due | Residential real estate loans
Financing Receivable Recorded Investment		378
Financial Asset, 60 to 89 Days Past Due | Commercial Real Estate
Financing Receivable Recorded Investment	12	327
Financial Asset, 60 to 89 Days Past Due | Total Loans
Financing Receivable Recorded Investment	103
Financial Asset, Greater than 90 Days Past Due
Financing Receivable Recorded Investment		2,730
Financial Asset, Greater than 90 Days Past Due | Consumer Loan
Financing Receivable Recorded Investment	95	193
Financial Asset, Greater than 90 Days Past Due | Commercial Loan
Financing Receivable Recorded Investment	148	810
Financial Asset, Greater than 90 Days Past Due | Residential real estate loans
Financing Receivable Recorded Investment	305	654
Financial Asset, Greater than 90 Days Past Due | Commercial Real Estate
Financing Receivable Recorded Investment	399	1,073
Financial Asset, Greater than 90 Days Past Due | Total Loans
Financing Receivable Recorded Investment	947
Financing Receivables, Current
Financing Receivable Recorded Investment		2,165,070
Financing Receivables, Current | Consumer Loan
Financing Receivable Recorded Investment	75,878	80,341
Financing Receivables, Current | Commercial Loan
Financing Receivable Recorded Investment	421,305	466,326
Financing Receivables, Current | Construction Real Estate
Financing Receivable Recorded Investment	122,742	107,472
Financing Receivables, Current | Residential real estate loans
Financing Receivable Recorded Investment	654,225	625,553
Financing Receivables, Current | Commercial Real Estate
Financing Receivable Recorded Investment	895,710	$ 885,378
Financing Receivables, Current | Total Loans
Financing Receivable Recorded Investment	$ 2,169,860