Regulatory Matters - Additional Information (Detail) |
12 Months Ended |
|---|---|
Mar. 31, 2026 | |
| Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements [Line Items] | |
| Capital adequacy ratio | 120.00% |
| Description of regulatory actions for not maintaining the minimum capital ratio concerning securities subsidiaries | A capital ratio of less than 140% will call for regulatory reporting and a capital ratio of less than 100% may lead to a temporary suspension of all or part of the business operations and further, to the cancellation of the license to act as a securities broker and dealer. |
| Minimum | Regulatory reporting | |
| Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements [Line Items] | |
| Capital adequacy ratio | 140.00% |
| Minimum | Temporary suspension | |
| Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements [Line Items] | |
| Capital adequacy ratio | 100.00% |