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Nature of Operations and Summary of Significant Accounting Policies - Additional Information (Detail) | 12 Months Ended
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Jun. 30, 2022 USD ($) Banking_Office | Jun. 30, 2021 USD ($)
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items] |  |
Number of full service banking offices | Banking_Office | 7 |
Interest-bearing deposits, maturity period (in months) | 3 years |
Liquid investments with original maturity period | 3 months |
Accrual of interest on loans due discontinued period, in days | 90 days |
Percentage of minimum likelihood of realized tax benefit upon settlement | 50.00% |
Cash, Uninsured Amount | $ 3,017,000,000 |
Federal home loan bank stock and federal reserve bank stock | 67,200,000,000 |
Long-Lived Asset Impairment | $ 0 | $ 0
Sales [Member] |  |
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items] |  |
Percentage of major customer revenues | 10.00% |

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