Financial Risk Management - Financial Effect of Collateral and Other Credit Enhancements on Loans and Advances for Borrowers Requiring Caution and Impaired Loans and Advances (Detail) - JPY (¥) ¥ in Millions |
Mar. 31, 2026 |
Mar. 31, 2025 |
|---|---|---|
| Disclosure of credit risk exposure [abstract] | ||
| Impaired loans and advances | ¥ 1,583,138 | ¥ 1,290,812 |
| Financial effect of collateral and other credit enhancements | ¥ 518,563 | ¥ 333,383 |