| Standard label: | Cash Segregated under Other Regulations |
| Name: | us-gaap:CashSegregatedUnderOtherRegulations |
| Documentation: | Cash deposited in a special reserve account for the exclusive benefit of customers pursuant to regulations other than SEC Regulations and the Commodity Exchange Act. |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | As Of (instant) |
| Balance type: | Debit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:CashSegregatedUnderOtherRegulations |
| Label | Role | Language |
| Cash Segregated under Other Regulations | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 942 210 50 1 | http://www.xbrl.org/2009/role/commonPracticeRef | 942 |