| Standard label: | Schedule of Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Grant Date Intrinsic Value [Table Text Block] |
| Name: | us-gaap:ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGrantDateIntrinsicValueTableTextBlock |
| Documentation: | Tabular disclosure of the total intrinsic value of options exercised (or share units converted), share-based liabilities paid, and the total fair value of shares vested during the year. |
| Object type: | cm:Level3TextBlock |
| 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:ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGrantDateIntrinsicValueTableTextBlock |
| Examples of this text block disclosure: | SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantsInPeriodGrantDateIntrinsicValue |
| Label | Role | Language |
| Schedule of Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Grant Date Intrinsic Value [Table Text Block] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 718 10 50 2 (d)(2) | http://fasb.org/us-gaap/role/ref/legacyRef | 718 |