Fair Value Measurements - Schedule of financial instruments (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2024	Jun. 30, 2024
Financial assets
Cash and cash equivalents	$ 75,347	$ 60,904
Interest-bearing time deposits	244	491
Stock in FHLB	8,972	8,713
Stock in Federal Reserve Bank of St. Louis	9,092	9,089
Loans receivable, net	3,912,081	3,797,287
Accrued interest receivable	28,949	23,826
Mortgage Servicing Assets, Fair Value Disclosure	2,419	2,448
Derivative financial instruments	1,320	20
Financial liabilities
Deposits	4,040,142	3,943,059
Securities sold under agreements to repurchase	15,000	9,398
Advances from FHLB	107,069	102,050
Accrued interest payable	11,668	12,868
Subordinated debt	23,169	23,156
Derivative financial instruments	1,294	15
Unrecognized financial instruments (net of contract amount)
Letters of credit	0
Lines of credit	0
Fair Value, Inputs, Level 1
Financial assets
Cash and cash equivalents	75,347	60,904
Financial liabilities
Deposits	2,520,687	2,607,653
Fair Value, Inputs, Level 2
Financial assets
Interest-bearing time deposits	244	491
Stock in FHLB	8,972	8,713
Stock in Federal Reserve Bank of St. Louis	9,092	9,089
Accrued interest receivable	28,949	23,826
Derivative financial instruments	1,320	20
Financial liabilities
Securities sold under agreements to repurchase	15,000	9,398
Advances from FHLB	107,124	100,468
Accrued interest payable	11,668	12,868
Derivative financial instruments	1,294	15
Fair Value, Inputs, Level 3
Financial assets
Loans receivable, net	3,848,447	3,639,657
Mortgage Servicing Assets, Fair Value Disclosure	2,419	2,448
Financial liabilities
Deposits	1,523,471	1,338,215
Subordinated debt	$ 20,881	$ 20,576