Fair Value of Financial Instruments - Summary of Quantitative Information about Level 3 Fair Value Measurements for Selected Financial Instruments Measured at Fair Value on Non-recurring Basis (Detail) $ in Thousands	Mar. 31, 2022 USD ($)	Jun. 30, 2021 USD ($)
Minimum [Member] | Measurement Input, Discount Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range or Rate Used	0.10
Maximum [Member] | Measurement Input, Discount Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range or Rate Used	0.20
Measured on a Non-Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 335	$ 337
Measured on a Non-Recurring Basis [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	335	337
Measured on a Non-Recurring Basis [Member] | Impaired Loans [Member] | Residential [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	307	312
Measured on a Non-Recurring Basis [Member] | Impaired Loans [Member] | Residential [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	307	312
Measured on a Non-Recurring Basis [Member] | Impaired Loans [Member] | Residential [Member] | Level 3 [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Discount Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	307	312
Measured on a Non-Recurring Basis [Member] | Impaired Loans [Member] | Home Equity Lines Of Credit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	28	25
Measured on a Non-Recurring Basis [Member] | Impaired Loans [Member] | Home Equity Lines Of Credit [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	28	25
Measured on a Non-Recurring Basis [Member] | Impaired Loans [Member] | Home Equity Lines Of Credit [Member] | Level 3 [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Discount Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 28	$ 25
Measured on a Non-Recurring Basis [Member] | Impaired Loans [Member] | Minimum [Member] | Residential [Member] | Level 3 [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Discount Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range or Rate Used	0.054	0.054
Measured on a Non-Recurring Basis [Member] | Impaired Loans [Member] | Minimum [Member] | Home Equity Lines Of Credit [Member] | Level 3 [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Discount Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range or Rate Used	0.054	0.054
Measured on a Non-Recurring Basis [Member] | Impaired Loans [Member] | Maximum [Member] | Residential [Member] | Level 3 [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Discount Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range or Rate Used	0.063	0.063
Measured on a Non-Recurring Basis [Member] | Impaired Loans [Member] | Maximum [Member] | Home Equity Lines Of Credit [Member] | Level 3 [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Discount Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range or Rate Used	0.063	0.063