Affiliated companies and other equity-method investees - Summary of balances and transactions with affiliated companies and other equity-method investees (Parenthetical) (Detail) - JPY (¥) ¥ in Millions |
12 Months Ended | ||
|---|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
Mar. 31, 2024 |
|
| Subsidiary or Equity Method Investee [Line Items] | |||
| Operating lease right of use asset | ¥ 138,708 | ¥ 156,791 | |
| Operating lease liabilities | 156,279 | 174,132 | |
| Proceeds from Sale of Property, Plant, and Equipment | 58,744 | (2,344) | ¥ (2,670) |
| Land and Building [Member] | Affiliated Entity [Member] | |||
| Subsidiary or Equity Method Investee [Line Items] | |||
| Proceeds from Sale of Property, Plant, and Equipment | 56,144 | ||
| Accounting Standards Update 2016-02 [Member] | |||
| Subsidiary or Equity Method Investee [Line Items] | |||
| Operating lease right of use asset | 19,547 | 20,664 | |
| Operating lease liabilities | ¥ 19,547 | ¥ 20,664 | |