Loans and Allowance for Credit Losses - Allowance for off-balance credit exposure (Details) - USD ($)	3 Months Ended		9 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2025	Mar. 31, 2024
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	$ 3,832,000	$ 4,596,000	$ 3,263,000	$ 6,288,000
Provision (benefit) charged to expense	(368,000)	(458,000)	201,000	(2,150,000)
Balance, end of period	3,464,000	4,138,000	3,464,000	4,138,000
Commercial and industrial
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	1,032,000	728,000	782,000	730,000
Provision (benefit) charged to expense	194,000	21,000	444,000	19,000
Balance, end of period	1,226,000	749,000	1,226,000	749,000
Agriculture production
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	127,000	157,000	37,000	107,000
Provision (benefit) charged to expense	70,000	(5,000)	160,000	45,000
Balance, end of period	197,000	152,000	197,000	152,000
Consumer
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	6,000	14,000	12,000	16,000
Provision (benefit) charged to expense			(6,000)	(2,000)
Balance, end of period	6,000	14,000	6,000	14,000
All other loans
Allowance for off-balance sheet credit exposure:
Balance, beginning of period				10,000
Provision (benefit) charged to expense	1,000		1,000	(10,000)
Balance, end of period	1,000		1,000
Secured by real estate | 1-4 residential real estate
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	229,000	136,000	140,000	126,000
Provision (benefit) charged to expense	(33,000)	7,000	56,000	17,000
Balance, end of period	196,000	143,000	196,000	143,000
Secured by real estate | Commercial Real Estate | Non-owner occupied
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	185,000	151,000	153,000	154,000
Provision (benefit) charged to expense	(17,000)	39,000	15,000	36,000
Balance, end of period	168,000	190,000	168,000	190,000
Secured by real estate | Commercial Real Estate | Owner occupied
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	169,000	175,000	136,000	182,000
Provision (benefit) charged to expense	5,000	(11,000)	38,000	(18,000)
Balance, end of period	174,000	164,000	174,000	164,000
Secured by real estate | Multi-family real estate
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	65,000	9,000	31,000	16,000
Provision (benefit) charged to expense	(3,000)	25,000	31,000	18,000
Balance, end of period	62,000	34,000	62,000	34,000
Secured by real estate | Construction and land development
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	1,965,000	3,179,000	1,912,000	4,897,000
Provision (benefit) charged to expense	(561,000)	(524,000)	(508,000)	(2,242,000)
Balance, end of period	1,404,000	2,655,000	1,404,000	2,655,000
Secured by real estate | Agriculture real estate
Allowance for off-balance sheet credit exposure:
Balance, beginning of period	54,000	47,000	60,000	50,000
Provision (benefit) charged to expense	(24,000)	(10,000)	(30,000)	(13,000)
Balance, end of period	$ 30,000	$ 37,000	$ 30,000	$ 37,000