Goodwill and intangible assets - Summary of Changes In Goodwill (Detail) - JPY (¥) ¥ in Millions |
12 Months Ended | |
|---|---|---|
Mar. 31, 2025 |
Mar. 31, 2024 |
|
| Disclosure of reconciliation of changes in goodwill [line items] | ||
| Balance at beginning of the fiscal year | ¥ 1,487,100 | ¥ 1,275,112 |
| Increase (decrease) due to: | ||
| Acquisitions | 44,424 | 70,791 |
| Disposals or classified as held for sale | 0 | (14,491) |
| Impairments | 0 | |
| Translation adjustments | (22,803) | 155,688 |
| Total changes | 21,621 | 211,988 |
| Balance at end of the fiscal year | 1,508,721 | 1,487,100 |
| Gross carrying amount [member] | ||
| Disclosure of reconciliation of changes in goodwill [line items] | ||
| Balance at beginning of the fiscal year | 1,884,627 | 1,649,041 |
| Increase (decrease) due to: | ||
| Balance at end of the fiscal year | 1,903,617 | 1,884,627 |
| Accumulated impairment [member] | ||
| Disclosure of reconciliation of changes in goodwill [line items] | ||
| Balance at beginning of the fiscal year | (397,527) | (373,929) |
| Increase (decrease) due to: | ||
| Balance at end of the fiscal year | ¥ (394,896) | ¥ (397,527) |