Pension and Other Employee Benefit Plans (Combined Funded Status and Amounts Recognized in Accompanying Consolidated Balance Sheets) (Parenthetical) (Detail) - JPY (¥) ¥ in Millions |
12 Months Ended | |
|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
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| Defined Benefit Plan Disclosure [Line Items] | ||
| Gain (loss) recognized | ¥ 0 | |
| Change in assumptions for defined benefit plans [member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Defined benefit plans, prior service costs recognised | ¥ 9,360 |
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- Definition Gains or losses recognized defined benefit plan settlement. No definition available.
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| X | ||||||||||
- Definition Amount, after tax, of accumulated other comprehensive (income) loss for cost (credit) of benefit change attributable to participants' prior service from plan amendment or plan initiation of defined benefit plan, that has not been recognized in net periodic benefit cost (credit). Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition 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. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Details
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