Loans and Allowance for Credit Losses - Loan portfolio aging analysis (Details)	9 Months Ended	12 Months Ended
	Mar. 31, 2025 USD ($) loan	Jun. 30, 2024 USD ($) loan
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	$ 4,023,698,000	$ 3,850,035,000
Number of PCD loans greater than 90 days past due | loan	2	1
Purchased credit-impaired loans	$ 520,000	$ 560,000
Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	24,444,000	9,201,000
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	6,611,000	3,128,000
60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	8,480,000	2,621,000
Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	9,353,000	3,452,000
Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	3,999,254,000	3,840,834,000
Construction and land development
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	323,499,000
Agriculture real estate
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	247,027,000
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	488,116,000	450,147,000
Commercial and industrial | Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	5,292,000	2,059,000
Commercial and industrial | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	986,000	641,000
Commercial and industrial | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,864,000	83,000
Commercial and industrial | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	2,442,000	1,335,000
Commercial and industrial | Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	482,824,000	448,088,000
Agriculture production
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	186,058,000	175,968,000
Agriculture production | Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	295,000	394,000
Agriculture production | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	20,000	50,000
Agriculture production | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	87,000
Agriculture production | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	188,000	344,000
Agriculture production | Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	185,763,000	175,574,000
Consumer
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	54,022,000	59,671,000
Consumer | Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	621,000	399,000
Consumer | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	490,000	311,000
Consumer | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	94,000	74,000
Consumer | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	37,000	14,000
Consumer | Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	53,401,000	59,272,000
All other loans
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	3,216,000	3,981,000
All other loans | Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	3,216,000	3,981,000
Secured by real estate | 1-4 residential real estate
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	978,908,000	925,397,000
Secured by real estate | 1-4 residential real estate | Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	6,999,000	3,641,000
Secured by real estate | 1-4 residential real estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	3,340,000	890,000
Secured by real estate | 1-4 residential real estate | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	810,000	2,087,000
Secured by real estate | 1-4 residential real estate | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	2,849,000	664,000
Secured by real estate | 1-4 residential real estate | Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	971,909,000	921,756,000
Secured by real estate | Commercial Real Estate | Non-owner occupied
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	897,125,000	899,770,000
Secured by real estate | Commercial Real Estate | Non-owner occupied | Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	5,135,000	107,000
Secured by real estate | Commercial Real Estate | Non-owner occupied | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable		107,000
Secured by real estate | Commercial Real Estate | Non-owner occupied | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	5,071,000
Secured by real estate | Commercial Real Estate | Non-owner occupied | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	64,000
Secured by real estate | Commercial Real Estate | Non-owner occupied | Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	891,990,000	899,663,000
Secured by real estate | Commercial Real Estate | Owner occupied
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	440,282,000	427,476,000
Secured by real estate | Commercial Real Estate | Owner occupied | Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	2,615,000	1,365,000
Secured by real estate | Commercial Real Estate | Owner occupied | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,043,000	305,000
Secured by real estate | Commercial Real Estate | Owner occupied | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	392,000
Secured by real estate | Commercial Real Estate | Owner occupied | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	1,180,000	1,060,000
Secured by real estate | Commercial Real Estate | Owner occupied | Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	437,667,000	426,111,000
Secured by real estate | Multi-family real estate
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	405,445,000	384,564,000
Secured by real estate | Multi-family real estate | Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	405,445,000	384,564,000
Secured by real estate | Construction and land development
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	323,499,000	290,541,000
Secured by real estate | Construction and land development | Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	355,000	628,000
Secured by real estate | Construction and land development | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	355,000	251,000
Secured by real estate | Construction and land development | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable		377,000
Secured by real estate | Construction and land development | Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	323,144,000	289,913,000
Secured by real estate | Agriculture real estate
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	247,027,000	232,520,000
Secured by real estate | Agriculture real estate | Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	3,132,000	608,000
Secured by real estate | Agriculture real estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	377,000	573,000
Secured by real estate | Agriculture real estate | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	162,000
Secured by real estate | Agriculture real estate | Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	2,593,000	35,000
Secured by real estate | Agriculture real estate | Current
Financing Receivable, Past Due [Line Items]
Total Loans Receivable	$ 243,895,000	$ 231,912,000