| Standard label: | Interim Period, Costs Not Allocable [Table Text Block] |
| Name: | us-gaap:InterimPeriodCostsNotAllocableTableTextBlock |
| Documentation: | Tabular disclosure of costs and expenses incurred during an interim period that cannot be readily identified with the activities or benefits of other interim periods and are charged to the interim period in which incurred. |
| 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:InterimPeriodCostsNotAllocableTableTextBlock |
| Label | Role | Language |
| Interim Period, Costs Not Allocable [Table Text Block] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 270 10 45 8 (b) | http://fasb.org/us-gaap/role/ref/legacyRef | 270 |