Disclosures About Fair Value of Assets - Reconciliation of Beginning and Ending Balances of Recurring Fair Value Measurements Recognized in Accompanying Balance Sheet (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2024	Jun. 30, 2024
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 3,548	$ 3,843
Transfers into Level 3	47	151
Transfers out of Level 3	(34)	(143)
Total realized and unrealized gains and losses included in net income	(138)	1
Settlements		(304)
Ending Balance	3,423	3,548
Total gains or losses for the period included in net income attributable to the change in unrealized gains or losses related to assets and liabilities still held at the reporting date	(138)	1
Obligations of State and Political Subdivisions [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	2,057	2,361
Settlements		(304)
Ending Balance	2,057	2,057
Mortgage Servicing Rights [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	1,491	1,482
Transfers into Level 3	47	151
Transfers out of Level 3	(34)	(143)
Total realized and unrealized gains and losses included in net income	(138)	1
Ending Balance	1,366	1,491
Total gains or losses for the period included in net income attributable to the change in unrealized gains or losses related to assets and liabilities still held at the reporting date	$ (138)	$ 1