| Standard label: | Effect of Fourth Quarter Events [Table Text Block] |
| Name: | us-gaap:EffectOfFourthQuarterEventsTextBlock |
| Documentation: | Tabular disclosure of transactions recognized in the fourth quarter. Includes, but is not limited to, disposals of components of an entity, unusual or infrequently occurring items, or both, effect from changes in accounting estimates, and effect of year-end adjustments. |
| 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:EffectOfFourthQuarterEventsTextBlock |
| Examples of this text block disclosure: | EffectOfFourthQuarterEvents |
| Label | Role | Language |
| Effect of Fourth Quarter Events [Table Text Block] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 270 10 50 2 | http://fasb.org/us-gaap/role/ref/legacyRef | 270 |