Derivative Financial Instruments (Summary of Notional and Fair Value Amounts of Credit Derivatives) (Detail) - JPY (¥) ¥ in Billions |
Mar. 31, 2026 |
Mar. 31, 2025 |
|---|---|---|
| Credit protection written | ||
| Credit Derivatives [Line Items] | ||
| Notional amount | ¥ 12,592 | ¥ 15,750 |
| Fair value | 91 | 164 |
| Credit protection written | Investment grade | ||
| Credit Derivatives [Line Items] | ||
| Notional amount | 9,191 | 9,201 |
| Fair value | 53 | 59 |
| Credit protection written | Non-investment grade | ||
| Credit Derivatives [Line Items] | ||
| Notional amount | 3,402 | 6,549 |
| Fair value | 38 | 106 |
| Credit protection purchased | ||
| Credit Derivatives [Line Items] | ||
| Notional amount | 14,499 | 18,097 |
| Fair value | ¥ (19) | ¥ (129) |
| 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
|
| X | ||||||||||
- Definition Fair value of credit risk derivative asset after deduction of credit risk derivative liability. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Nominal or face amount used to calculate payments on the derivative asset. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|