Business Combinations - Additional Information (Detail) - MUFG Union Bank [Member] - Forecast [Member] $ in Billions	6 Months Ended
Dec. 31, 2022 USD ($) Branches shares
Business Acquisition [Line Items]
Business combination, Consideration transferred	$ 8.0
Payments to acquire businesses, gross	5.5
Business combination, Recognized identifiable assets acquired and liabilities assumed, Assets	105.0
Business combination, Recognized identifiable assets acquired and liabilities assumed, Financial liabilities	58.0
Business combination, Recognized identifiable assets acquired and liabilities assumed, Deposits	$ 90.0
Number of branches acquired \| Branches	300
Common Stock [Member]
Business Acquisition [Line Items]
Business acquisition, Equity interest issued or issuable, Number of shares \| shares	44,000,000

Number of shares of equity interests issued or issuable to acquire entity.

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Amount of assets acquired at the acquisition date.

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The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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Business combination number of branches acquired.

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