Financial instruments - Additional Information (Detail) - JPY (¥) |
12 Months Ended | |
|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
|
| Disclosure of detailed information about financial instruments [line items] | ||
| Reclassification Adjustment of Financial Liabilities At Amortised Cost | “Current portion of long-term debt” of 90,495 million yen and “Long-term debt” of 508,975 million yen as of March 31, 2025 have been reclassified to “Lease liabilities” of 599,470 million yen. | |
| Debt securities [member] | ||
| Disclosure of detailed information about financial instruments [line items] | ||
| Transfers out of Level 2 into Level 1 of fair value hierarchy, assets held at end of reporting period | ¥ 0 | ¥ 2,557,000,000 |
| Transfers out of Level 1 into Level 2 of fair value hierarchy, assets held at end of reporting period | 0 | 2,081,000,000 |
| Equity securities [member] | ||
| Disclosure of detailed information about financial instruments [line items] | ||
| Transfers out of level 2 into level 1 of equity securities | ¥ 0 | ¥ 1,480,000,000 |