cm:Level1TextBlock: us-gaap:AdditionalFinancialInformationDisclosureTextBlock
| Additional Financial Information Disclosure [Text Block] |
| us-gaap:AdditionalFinancialInformationDisclosureTextBlock |
| The entire disclosures of supplemental information, including descriptions and amounts, related to the balance sheet, income statement, and/or cash flow statement. |
| cm:Level1TextBlock |
| Text Block (HTML) (nonnum:textBlockItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:AdditionalFinancialInformationDisclosureTextBlock |
| AdditionalFinancialInformationDisclosure |