Call Money and Funds Purchased (Summary of Funds Transactions) (Detail) - JPY (¥) ¥ in Millions |
12 Months Ended | |
|---|---|---|
Mar. 31, 2025 |
Mar. 31, 2024 |
|
| Call Money and Funds Purchased Transactions [Line Items] | ||
| Amount | ¥ 5,016,678 | ¥ 5,094,171 |
| Weighted average interest rate | 0.63% | 0.09% |
| Minimum | ||
| Call Money and Funds Purchased Transactions [Line Items] | ||
| Principal range of maturities | 1 day | 1 day |
| Maximum | ||
| Call Money and Funds Purchased Transactions [Line Items] | ||
| Principal range of maturities | 30 days | 30 days |