Accumulated Other Comprehensive Income (Loss) - Components of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Accumulated Other Comprehensive Income [Line Items]
Beginning balance	$ (21,648)	$ (17,346)
Other comprehensive income (loss) before reclassification	947	(4,574)
Amounts reclassified from accumulated other comprehensive income (loss)	0	122
Net current period other comprehensive income	142	150
Ending balance	(20,559)	(21,648)
Unrealized Gains and Losses on Available-for- Sale Securities [Member]
Accumulated Other Comprehensive Income [Line Items]
Beginning balance	(21,715)	(17,263)
Other comprehensive income (loss) before reclassification	947	(4,574)
Amounts reclassified from accumulated other comprehensive income (loss)	0	122
Net current period other comprehensive income	0	0
Ending balance	(20,768)	(21,715)
Defined Benefit Pension Items [Member]
Accumulated Other Comprehensive Income [Line Items]
Beginning balance	67	(83)
Other comprehensive income (loss) before reclassification	0	0
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Net current period other comprehensive income	142	150
Ending balance	$ 209	$ 67