| Standard label: | Lease, Cost [Table Text Block] |
| Name: | us-gaap:LeaseCostTableTextBlock |
| Documentation: | Tabular disclosure of lessee's lease cost. Includes, but is not limited to, interest expense for finance lease, amortization of right-of-use asset for finance lease, operating lease cost, short-term lease cost, variable lease cost and sublease income. |
| 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:LeaseCostTableTextBlock |
| Label | Role | Language |
| Lease, Cost [Table Text Block] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 842 20 50 4 | http://www.xbrl.org/2009/role/commonPracticeRef | 842 |