Loans and Allowance for Credit Losses - Allowance for off-balance credit exposure (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2020
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	$ 1,805	$ 1,959
Provision (benefit) charged to expense	1,553	(422)	$ 648
Balance, end of period	3,358	1,805	1,959
Impact of adoption ASU 2016-13
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	268
Balance, end of period		268
Residential Real Estate
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	37	19
Provision (benefit) charged to expense	21	(17)
Balance, end of period	58	37	19
Residential Real Estate | Impact of adoption ASU 2016-13
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	35
Balance, end of period		35
Construction Real Estate
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	502	769
Provision (benefit) charged to expense	1,676	(100)
Balance, end of period	2,178	502	769
Construction Real Estate | Impact of adoption ASU 2016-13
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	(167)
Balance, end of period		(167)
Commercial Real Estate
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	188	172
Provision (benefit) charged to expense	233	(79)
Balance, end of period	421	188	172
Commercial Real Estate | Impact of adoption ASU 2016-13
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	95
Balance, end of period		95
Consumer loans
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	218	153
Provision (benefit) charged to expense	(157)	(132)
Balance, end of period	61	218	153
Consumer loans | Impact of adoption ASU 2016-13
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	197
Balance, end of period		197
Commercial loans
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	860	846
Provision (benefit) charged to expense	(220)	(94)
Balance, end of period	640	860	$ 846
Commercial loans | Impact of adoption ASU 2016-13
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	$ 108
Balance, end of period		$ 108