Financial Risk Management - Balance of Loans and Advances and Deposits (Detail) - JPY (¥) ¥ in Millions |
Mar. 31, 2026 |
Mar. 31, 2025 |
|---|---|---|
| Disclosure Of Loans and advances, and Deposits [abstract] | ||
| Loans and advances | ¥ 130,516,241 | ¥ 125,190,819 |
| Deposits | ¥ 201,930,427 | ¥ 190,022,742 |