Short-term borrowings and long-term debt - Summary of Pledged Assets as Collateral (Detail) ¥ in Millions |
Mar. 31, 2025
JPY (¥)
|
|---|---|
| Certain Assets Pledged As Collateral For Short Term Borrowings And Long Term Debt [Line Items] | |
| Securities | ¥ 332,867 |
| Securities | 140,212 |
| Securities [member] | |
| Certain Assets Pledged As Collateral For Short Term Borrowings And Long Term Debt [Line Items] | |
| Financial assets pledged as collateral for liabilities or contingent liabilities | 1,595,016 |
| Housing Loans in The Banking Business [member] | |
| Certain Assets Pledged As Collateral For Short Term Borrowings And Long Term Debt [Line Items] | |
| Financial assets pledged as collateral for liabilities or contingent liabilities | ¥ 961,286 |