cm:Level3TextBlock: us-gaap:ScheduleOfSecuritiesOwnedAndSoldNotYetPurchasedAtFairValueTextBlock
| Schedule of Securities Owned and Sold, Not yet Purchased, at Fair Value [Table Text Block] |
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| Tabular disclosure of financial instruments held by a broker-dealer for its own account (proprietary securities) for trading or investment purposes that are carried at fair value including securities sold, not yet purchased. |
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