Fair Value (Reconciliation for All Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3) (Parenthetical) (Detail) - JPY (¥) ¥ in Billions |
12 Months Ended | |
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Mar. 31, 2026 |
Mar. 31, 2025 |
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| Fair Value Disclosures [Abstract] | ||
| Unrealized gains (losses) in OCI related to Available-for-sale securities | ¥ (6) | ¥ (10) |
| Unrealized gains (losses) in OCI related to Long-term debt | ¥ (6) | ¥ 6 |
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- References No definition available.
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- Definition Amount, after tax, before reclassification adjustment, of unrealized gain (loss) from increase (decrease) in instrument-specific credit risk of financial liability measured under fair value option. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount, after tax and before adjustment, of unrealized holding gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Excludes unrealized gain (loss) on investment in debt security measured at amortized cost (held-to-maturity) from transfer to available-for-sale. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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