cm:Level3TextBlock: us-gaap:ScheduleOfDueToFromBrokerDealersAndClearingOrganizationsTextBlock
| Schedule of Due to (from) Broker-Dealers and Clearing Organizations [Table Text Block] |
| us-gaap:ScheduleOfDueToFromBrokerDealersAndClearingOrganizationsTextBlock |
| Tabular disclosure of amounts receivable from and payable to broker-dealers and clearing organizations, including securities failed to receive, deposits received for securities loaned, amounts payable to clearing organizations related to open transactions, floor brokerage payables and payables for commodities futures accounts liquidating to an equity balance on a broker-dealer's records. |
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| us-gaap:ScheduleOfDueToFromBrokerDealersAndClearingOrganizationsTextBlock |