Financial Risk Management - Regulatory Capital Requirements (Detail) - JPY (¥) ¥ in Billions |
Mar. 31, 2026 |
Mar. 31, 2025 |
|---|---|---|
| Disclosure of objectives, policies and processes for managing capital [abstract] | ||
| Total risk-weighted capital ratio | 15.69% | 15.18% |
| Tier 1 risk-weighted capital ratio | 14.49% | 14.23% |
| Common Equity Tier 1 risk-weighted capital ratio | 12.41% | 12.44% |
| Total capital (Common Equity Tier 1 capital + Additional Tier 1 capital + Tier 2 capital) | ¥ 15,865.9 | ¥ 14,144.1 |
| Tier 1 capital (Common Equity Tier 1 capital + Additional Tier 1 capital) | 14,655.9 | 13,258.8 |
| Common Equity Tier 1 capital | 12,544.0 | 11,585.1 |
| Risk-weighted assets | 101,078.2 | 93,117.1 |
| The amount of minimum total capital requirements | ¥ 8,086.3 | ¥ 7,449.4 |