| Standard label: | Discontinued Operations, Policy [Policy Text Block] | 
| Name: | us-gaap:DiscontinuedOperationsPolicyTextBlock | 
| Documentation: | Disclosure of accounting policy for discontinued operations. Includes, but is not limited to, method of interest allocation to a discontinued operation. | 
| Object type: | cm:Level2TextBlock | 
| 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:DiscontinuedOperationsPolicyTextBlock | 
| Label | Role | Language | 
| Discontinued Operations, Policy [Policy Text Block] | http://www.xbrl.org/2003/role/label | en-US | 
| Reference | Role | Topic | 
| FASB Accounting Standards Codification 205 20 50 1 | http://fasb.org/us-gaap/role/ref/legacyRef | 205 | 
| FASB Accounting Standards Codification 205 20 S99 3 | http://fasb.org/us-gaap/role/ref/legacyRef | 205 | 
| FASB Accounting Standards Codification 235 10 50 3 | http://fasb.org/us-gaap/role/ref/legacyRef | 235 | 
| FASB Accounting Standards Codification 260 10 50 1 | http://fasb.org/us-gaap/role/ref/legacyRef | 260 |