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Securities - Amortized Cost and Fair Value of Available-for-Sale Securities by Contractual Maturity (Detail) - USD ($)	Sep. 30, 2025	Jun. 30, 2025
Debt Securities, Available-for-sale [Line Items]
Within one year, Amortized Cost	$ 0
One to five years, Amortized Cost	2,642,000
Five to ten years, Amortized Cost	5,949,000
After ten years, Amortized Cost	8,623,000
Amortized Cost	17,214,000
Amortized Cost	210,449,000	$ 210,889,000
Within one year, Fair Value	0
One to five years, Fair Value	2,536,000
Five to ten years, Fair Value	5,603,000
After ten years, Fair Value	7,340,000
Fair Value	15,479,000
Fair Value	189,824,000	187,753,000
Mortgage-backed securities – GSE residential [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	193,235,000	192,261,000
Fair Value	$ 174,345,000	$ 171,079,000

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