| Standard label: | Postemployment Benefits Disclosure [Text Block] |
| Name: | us-gaap:PostemploymentBenefitsDisclosureTextBlock |
| Documentation: | The entire disclosure for postemployment benefits, which may include supplemental unemployment benefits, obligations recognized for all types of benefits provided to former or inactive employees, their beneficiaries, and covered dependents after employment but before retirement. Disclosure may also include discussion that an obligation for postemployment benefits is not accrued in accordance with regulation only because the amount cannot be reasonably estimated. |
| Object type: | cm:Level1TextBlock |
| 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:PostemploymentBenefitsDisclosureTextBlock |
| Examples of this text block disclosure: | PostemploymentBenefits |
| Label | Role | Language |
| Postemployment Benefits Disclosure [Text Block] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 712 | http://fasb.org/us-gaap/role/ref/legacyRef | 712 |