Liabilities for Quality Assurance - Summary of Net Change in Liabilities for Quality Assurances (Detail) - JPY (¥) ¥ in Millions |
12 Months Ended | ||
|---|---|---|---|
Mar. 31, 2025 |
Mar. 31, 2024 |
Mar. 31, 2023 |
|
| Liabilities for quality assurances [Abstract] | |||
| Liabilities for quality assurance at beginning of year | ¥ 1,836,314 | ¥ 1,686,357 | ¥ 1,555,711 |
| Additional provisions | 689,804 | 489,967 | 400,419 |
| Utilization | (550,006) | (340,872) | (229,623) |
| Reversals | (18,157) | (37,664) | (59,758) |
| Other | 7,793 | 38,526 | 19,608 |
| Liabilities for quality assurance at end of year | ¥ 1,965,748 | ¥ 1,836,314 | ¥ 1,686,357 |