Loans and Advances to Customers - Schedule of Laons and Advances to Customers (Parenthetical) (Details) - JPY (¥) ¥ in Millions |
Mar. 31, 2026 |
Mar. 31, 2025 |
|---|---|---|
| Loans And Advances To Customers [Abstract] | ||
| Percentage of loans acquired from financial institution | 1.00% | 1.00% |
| Loans acquired from financial institution | ¥ 175,950 | ¥ 187,471 |