Subsequent events - Additional Information (Detail) - Common Stock [Member] ¥ in Billions |
4 Months Ended | ||
|---|---|---|---|
|
Apr. 22, 2026
shares
|
Feb. 02, 2026 |
Aug. 31, 2026
JPY (¥)
shares
|
|
| Subsequent Event [Line Items] | |||
| Stock repurchase program period description | November 17, 2025 to March 31, 2026 | ||
| Subsequent Event [Member] | |||
| Subsequent Event [Line Items] | |||
| Stock repurchase program period description | May 18, 2026, to August 31, 2026 | ||
| The total payout ratio | 50.00% | ||
| Percentage of stock repurchased of outstanding shares | 1.00% | ||
| Share Repurchase Program, Authorized, Amount | ¥ | ¥ 100 | ||
| Share Repurchase Program, Authorized, Number of Shares | 25,000,000 | ||
| Share cancellation approval dates | November 14 | ||
| Shares cancelled, number of shares | 47,016,600 | ||
| Shares cancelled percentage | 1.9 |