Research and Development Cost - Disclosure of Breakdown of Research and Development Expense (Detail) - JPY (¥) ¥ in Millions |
12 Months Ended | ||
|---|---|---|---|
Mar. 31, 2025 |
Mar. 31, 2024 |
Mar. 31, 2023 |
|
| Disclosure of research and development cost | |||
| Research and development expenditures incurred during the year | ¥ 1,326,496 | ¥ 1,202,373 | ¥ 1,241,686 |
| Total | 1,377,018 | 1,238,271 | 1,224,564 |
| Capitalised development expenditure [Member] | |||
| Disclosure of research and development cost | |||
| Amount capitalized | (111,546) | (124,788) | (181,634) |
| Intangible assets under development [Member] | |||
| Disclosure of research and development cost | |||
| Amortization of capitalized development costs | ¥ 162,068 | ¥ 160,686 | ¥ 164,512 |