Fair Value of Financial Instruments - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jun. 30, 2020 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value transfers between levels	$ 0		$ 0
Fair value assets transferred from level 2 to level 3	2,000,000.0		2,000,000.0
Carrying amount of loans	1,285,886,000		1,285,886,000			$ 1,229,451,000
Remaining valuation allowance	8,711,000	$ 7,865,000	8,711,000	$ 7,865,000	$ 8,429,000	7,881,000	$ 8,677,000	$ 8,639,000
Net charge-offs	24,000	27,000	142,000	268,000
Provision for loan losses	286,000	$ (894,000)	563,000	(678,000)
Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying amount of loans	454,000		454,000			458,000
Remaining valuation allowance	$ 118,000		118,000			$ 121,000
Net charge-offs			0	0
Provision for loan losses			$ 3,000	$ 1,000
Minimum [Member] | Measurement Input, Discount Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rates	0.10		0.10
Maximum [Member] | Measurement Input, Discount Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rates	0.20		0.20