| Standard label: | Other Nonoperating Income and Expense [Text Block] |
| Name: | us-gaap:OtherNonoperatingIncomeAndExpenseTextBlock |
| Documentation: | The entire disclosure for the components of non-operating income or non-operating expense, including, but not limited to, amounts earned from dividends, interest on securities, gain (loss) on securities sold, equity earnings of unconsolidated affiliates, gain (loss) on sales of business, interest expense and other miscellaneous income or expense items. |
| Object type: | cm:Level1TextBlock |
| Data type: | Text Block (HTML) (nonnum:textBlockItemType) |
| Period type: | For Period (duration) |
| Balance type: | (no balance type) |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:OtherNonoperatingIncomeAndExpenseTextBlock |
| Examples of this text block disclosure: | OtherNonoperatingIncomeAndExpenseDisclosure |
| Label | Role | Language |
| Other Nonoperating Income and Expense [Text Block] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |