Obligations under Guarantees and Other Off-balance Sheet Instruments (Contractual Amounts with Regard to Other Off-balance Sheet Instruments) (Detail) - JPY (¥) ¥ in Billions |
Mar. 31, 2025 |
Mar. 31, 2024 |
|---|---|---|
| Commitments to extend credit | ||
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | ||
| Contractual amounts with regard to other off-balance sheet instruments | ¥ 96,370 | ¥ 94,414 |
| Commercial letters of credit | ||
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | ||
| Contractual amounts with regard to other off-balance sheet instruments | 717 | 974 |
| Commitments to make investments | ||
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | ||
| Contractual amounts with regard to other off-balance sheet instruments | ¥ 718 | ¥ 674 |