| Standard label: | Schedule of Investments in and Advances to Affiliates, Schedule of Investments [Table Text Block] |
| Name: | us-gaap:ScheduleOfInvestmentsInAndAdvancesToAffiliatesScheduleOfInvestmentsTableTextBlock |
| Documentation: | A tabular presentation of the information summarizing investments in and advances to majority-owned subsidiaries, other controlled companies, and other affiliates, as prescribed by the SEC. It reflects specified information about ownership, financial results from, and financial position in such entities. Includes the tabular presentations that disaggregate investments in and advances to majority-owned subsidiaries, other controlled companies, and other affiliates. |
| 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:ScheduleOfInvestmentsInAndAdvancesToAffiliatesScheduleOfInvestmentsTableTextBlock |
| Label | Role | Language |
| Schedule of Investments in and Advances to Affiliates, Schedule of Investments [Table Text Block] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |