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, 2026 |
Mar. 31, 2025 |
|---|---|---|
| Commitments to extend credit | ||
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | ||
| Contractual amounts with regard to other off-balance sheet instruments | ¥ 106,737.0 | ¥ 96,370.0 |
| Commercial letters of credit | ||
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | ||
| Contractual amounts with regard to other off-balance sheet instruments | 966.0 | 717.0 |
| Commitments to make investments | ||
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | ||
| Contractual amounts with regard to other off-balance sheet instruments | 1,738.0 | ¥ 718.0 |
| Commitments to make investments | Shriram Finance Limited | ||
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | ||
| Contractual amounts with regard to other off-balance sheet instruments | ¥ 712.9 |