Income Taxes - Additional Information (Detail) - JPY (¥) ¥ in Millions |
12 Months Ended | ||
|---|---|---|---|
Mar. 31, 2025 |
Mar. 31, 2024 |
Mar. 31, 2023 |
|
| Statements [Line Items] | |||
| Temporary differences total | ¥ 5,667,006 | ¥ 4,630,892 | |
| Estimated amount of additional deferred tax liability if the undistributed earnings were to be distributed in the future | ¥ 245,292 | ¥ 232,645 | |
| Statutory tax rate | 30.90% | 30.90% | 30.90% |