Fair Value of Financial Instruments - Additional Information (Detail)	6 Months Ended
	Dec. 31, 2018 USD ($) Security	Jun. 30, 2018 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available for sale, Fair value	$ 543,832,000	$ 590,562,000
Assets, Fair Value	688,711,000	756,966,000
Financing receivable, allowance for credit losses, individually evaluated for impairment	352,000	306,000
Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value	4,299,000	4,469,000
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value	288,000
Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available for sale, Fair value	543,832,000	590,562,000
Loan Origination Commitments [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Pipeline of loans held-for-sale	4,600,000	10,800,000
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available for sale, Fair value	1,000,000	1,000,000
Assets, Fair Value	1,000,000	1,000,000
Significant Unobservable Inputs (Level 3) [Member] | Impaired Loans [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financing receivable, allowance for credit losses, individually evaluated for impairment	352,000	306,000
Loans and Leases Receivable, Gross	4,700,000	4,800,000
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value	4,299,000	4,469,000
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value	$ 288,000	$ 0
Significant Unobservable Inputs (Level 3) [Member] | Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Number of trust preferred securities | Security	1
Significant Unobservable Inputs (Level 3) [Member] | Debt Securities [Member] | One Trust Preferred Security [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available for sale, Fair value	$ 1,000,000