Income Taxes - Summary of Unrecognized Deferred Tax Assets on Tax Losses Carryforwards (Detail) - JPY (¥) ¥ in Millions |
Mar. 31, 2026 |
Mar. 31, 2025 |
|---|---|---|
| Disclosure details of carry forward details of tax losses unutilised for which no deferred tax assets are recognised [Line items] | ||
| Tax losses carryforward | ¥ 978,821 | ¥ 841,136 |
| Within 5 years [Member] | ||
| Disclosure details of carry forward details of tax losses unutilised for which no deferred tax assets are recognised [Line items] | ||
| Tax losses carryforward | 53,099 | 4,323 |
| Between 5 and 10 years [Member] | ||
| Disclosure details of carry forward details of tax losses unutilised for which no deferred tax assets are recognised [Line items] | ||
| Tax losses carryforward | 313,330 | 319,631 |
| Later than 10 years [Member] | ||
| Disclosure details of carry forward details of tax losses unutilised for which no deferred tax assets are recognised [Line items] | ||
| Tax losses carryforward | ¥ 612,392 | ¥ 517,182 |