| Standard label: | Principal Transactions Revenue, Net |
| Name: | us-gaap:PrincipalTransactionsRevenue |
| Documentation: | Amount of realized and unrealized gain (loss) resulting from the difference between acquisition price and selling price or fair value of trading assets and trading liabilities, and from the firm's direct investment activity, conducted separately from customer trading activities, including, but not limited to, investments in private equity, alternative investment products, real estate, and exchanges and memberships. |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | For Period (duration) |
| Balance type: | Credit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:PrincipalTransactionsRevenue |
| Label | Role | Language |
| Principal Transactions Revenue, Net | http://www.xbrl.org/2003/role/label | en-US |
| Principal Transactions Revenue, Net, Total | http://www.xbrl.org/2003/role/totalLabel | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 940 320 45 5 | http://fasb.org/us-gaap/role/ref/legacyRef | 940 |
| Part Of Roll Up: |
| us-gaap:Revenues |