| Standard label: | Equity Method Investments [Table Text Block] |
| Name: | us-gaap:EquityMethodInvestmentsTextBlock |
| Documentation: | Tabular disclosure of equity method investments including, but not limited to, name of each investee or group of investments, percentage ownership, difference between recorded amount of an investment and the value of the underlying equity in the net assets, and summarized financial information. |
| 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:EquityMethodInvestmentsTextBlock |
| Examples of this text block disclosure: | EquityMethodInvestments |
| Label | Role | Language |
| Equity Method Investments [Table Text Block] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 323 10 50 3 | http://fasb.org/us-gaap/role/ref/legacyRef | 323 |