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New Accounting Pronouncements - Schedule Of Impact Of ASU 2016-13 Adoption (Detail) - USD ($) | Dec. 31, 2022 | Sep. 30, 2022 | Jul. 01, 2022 | Jun. 30, 2022 | Dec. 31, 2021 | Sep. 30, 2021 | Jun. 30, 2021
--- | --- | --- | --- | --- | --- | --- | ---
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses | $ 7,166,000 | $ 7,023,000 |  | $ 7,052,000 | $ 6,395,000 | $ 6,470,000 | $ 6,599,000
Off-Balance-Sheet, Credit Loss, Liability | 434,000 |  | $ 496,000 | 0 |  |  |
Allowance For Credit Losses As Reported Under ASU 201613 [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | 7,099,000 |  |  |  |
Off-Balance-Sheet, Credit Loss, Liability |  |  | 496,000 |  |  |  |
Allowance For Credit Loss Before ASU 201613 Adoption [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | 7,052,000 |  |  |  |
Off-Balance-Sheet, Credit Loss, Liability |  |  | 0 |  |  |  |
Impact On Allowance Of ASU 201613 Adoption [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | 47,000 |  |  |  |
Off-Balance-Sheet, Credit Loss, Liability |  |  | 496,000 |  |  |  |
Commercial Portfolio Segment [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses | 871,000 | 1,090,000 |  | 2,025,000 | 1,521,000 | 1,571,000 | 1,740,000
Commercial Portfolio Segment [Member] | Allowance For Credit Losses As Reported Under ASU 201613 [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | 1,207,000 |  |  |  |
Commercial Portfolio Segment [Member] | Allowance For Credit Loss Before ASU 201613 Adoption [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | 2,025,000 |  |  |  |
Commercial Portfolio Segment [Member] | Impact On Allowance Of ASU 201613 Adoption [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | (818,000) |  |  |  |
Consumer Portfolio Segment [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses | 93,000 | 83,000 |  | 80,000 | 69,000 | 63,000 | 62,000
Consumer Portfolio Segment [Member] | Allowance For Credit Losses As Reported Under ASU 201613 [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | 93,000 |  |  |  |
Consumer Portfolio Segment [Member] | Allowance For Credit Loss Before ASU 201613 Adoption [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | 80,000 |  |  |  |
Consumer Portfolio Segment [Member] | Impact On Allowance Of ASU 201613 Adoption [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | 13,000 |  |  |  |
Real Estate Loans One To Four Family Including Home Equity Loans [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses | 1,722,000 | 1,537,000 |  | 1,028,000 | 1,082,000 | 974,000 | 967,000
Real Estate Loans One To Four Family Including Home Equity Loans [Member] | Allowance For Credit Losses As Reported Under ASU 201613 [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | 1,410,000 |  |  |  |
Real Estate Loans One To Four Family Including Home Equity Loans [Member] | Allowance For Credit Loss Before ASU 201613 Adoption [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | 1,028,000 |  |  |  |
Real Estate Loans One To Four Family Including Home Equity Loans [Member] | Impact On Allowance Of ASU 201613 Adoption [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | 382,000 |  |  |  |
Real Estate Loans Multi Family [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses | 1,402,000 | 1,284,000 |  | 1,375,000 | 1,400,000 | 1,562,000 | 1,674,000
Real Estate Loans Multi Family [Member] | Allowance For Credit Losses As Reported Under ASU 201613 [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | 1,235,000 |  |  |  |
Real Estate Loans Multi Family [Member] | Allowance For Credit Loss Before ASU 201613 Adoption [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | 1,375,000 |  |  |  |
Real Estate Loans Multi Family [Member] | Impact On Allowance Of ASU 201613 Adoption [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | (140,000) |  |  |  |
Commercial Real Estate Portfolio Segment [Member] | Allowance For Credit Losses As Reported Under ASU 201613 [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | 2,370,000 |  |  |  |
Commercial Real Estate Portfolio Segment [Member] | Allowance For Credit Loss Before ASU 201613 Adoption [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | 1,985,000 |  |  |  |
Commercial Real Estate Portfolio Segment [Member] | Impact On Allowance Of ASU 201613 Adoption [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | 385,000 |  |  |  |
Real Estate Loans Home Equity Lines Of Credit [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses | 101,000 | 94,000 |  | 70,000 | 62,000 | 63,000 | 67,000
Real Estate Loans Home Equity Lines Of Credit [Member] | Allowance For Credit Losses As Reported Under ASU 201613 [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | 103,000 |  |  |  |
Real Estate Loans Home Equity Lines Of Credit [Member] | Allowance For Credit Loss Before ASU 201613 Adoption [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | 70,000 |  |  |  |
Real Estate Loans Home Equity Lines Of Credit [Member] | Impact On Allowance Of ASU 201613 Adoption [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | 33,000 |  |  |  |
Construction Loans [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses | $ 585,000 | $ 549,000 |  | $ 489,000 | $ 299,000 | $ 321,000 | $ 258,000
Construction Loans [Member] | Allowance For Credit Losses As Reported Under ASU 201613 [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | 681,000 |  |  |  |
Construction Loans [Member] | Allowance For Credit Loss Before ASU 201613 Adoption [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | 489,000 |  |  |  |
Construction Loans [Member] | Impact On Allowance Of ASU 201613 Adoption [Member] |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |
Allowance for loan losses |  |  | $ 192,000 |  |  |  |

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