| Standard label: | Financial Instruments Sold, Not yet Purchased, at Fair Value |
| Name: | us-gaap:FinancialInstrumentsSoldNotYetPurchasedAtFairValue |
| Documentation: | Fair value of obligations incurred from short sales. |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | As Of (instant) |
| Balance type: | Credit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:FinancialInstrumentsSoldNotYetPurchasedAtFairValue |
| Label | Role | Language |
| Financial Instruments Sold, Not yet Purchased, at Fair Value | http://www.xbrl.org/2003/role/label | en-US |
| Financial Instruments Sold, Not yet Purchased, at Fair Value, Total | http://www.xbrl.org/2003/role/totalLabel | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 940 320 35 1 (b) | http://fasb.org/us-gaap/role/ref/legacyRef | 940 |
| Part Of Roll Up: |
| us-gaap:FinancialLiabilitiesFairValueDisclosure |