| Standard label: | Reconciliation of Other Significant Reconciling Items from Segments to Consolidated [Table Text Block] |
| Name: | us-gaap:ReconciliationOfOtherSignificantReconcilingItemsFromSegmentsToConsolidatedTextBlock |
| Documentation: | Tabular disclosure of each significant reconciling item, other than profit (loss), revenues, or assets, in the reconciliation of totals of such items in reportable segments to the entity's corresponding consolidated amount. |
| 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:ReconciliationOfOtherSignificantReconcilingItemsFromSegmentsToConsolidatedTextBlock |
| Examples of this text block disclosure: | ReconciliationOfOtherSignificantReconcilingItemsfromSegmentsToConsolidated |
| Label | Role | Language |
| Reconciliation of Other Significant Reconciling Items from Segments to Consolidated [Table Text Block] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 280 10 50 30 (d) | http://fasb.org/us-gaap/role/ref/legacyRef | 280 |
| FASB Accounting Standards Codification 280 10 50 31 | http://fasb.org/us-gaap/role/ref/legacyRef | 280 |