| Standard label: | Qualitative and Quantitative Information, Transferor's Continuing Involvement [Table Text Block] |
| Name: | us-gaap:QualitativeAndQuantitativeInformationTransferorsContinuingInvolvementTableTextBlock |
| Documentation: | Tabular disclosure of a transferor's continuing involvement with financial assets transferred to a transferee in a securitization, asset-backed financing arrangement, or similar transfer. Such disclosure would, at a minimum, contain information allowing for an assessment of the reasons for the transferor's continuing involvement, the risks related to the transferred financial assets to which the transferor continues to be exposed, and the extent of change to the transferor's risk profile due to the transfer (including, but not limited to, credit risk, interest rate risk, other). |
| 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:QualitativeAndQuantitativeInformationTransferorsContinuingInvolvementTableTextBlock |
| Label | Role | Language |
| Qualitative and Quantitative Information, Transferor's Continuing Involvement [Table Text Block] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 860 20 50 4 | http://fasb.org/us-gaap/role/ref/legacyRef | 860 |