Loans - Troubled Debt Restructurings On Financing Receivables (Parenthetical) (Detail)	12 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Financing Receivable, Modifications [Line Items]
Financing receivable modified weighted average term increase from modification	20 months 6 days	11 months
Financing Receivable, Modified, Weighted Average Interest Rate Decrease from Modification	1.00%	0.50%

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Percentage of decrease in weighted average contractual interest rate of financing receivable modified for debtor experiencing financial difficulty.

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- Definition

Period of increase in weighted average maturity of financing receivable modified for debtor experiencing financial difficulty, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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