| Standard label: | Schedule of Changes in Fair Value of Plan Assets [Table Text Block] |
| Name: | us-gaap:ScheduleOfChangesInFairValueOfPlanAssetsTableTextBlock |
| Documentation: | Tabular disclosure of the reconciliation of beginning and ending balances of the fair value of plan assets of pension plans and/or other employee benefit plans showing separately, if applicable, the effects during the period attributable to each of the following: actual return on plan assets, foreign currency exchange rate changes, contributions by the employer, contributions by plan participants, benefits paid, business combinations, divestitures, and settlements. |
| 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:ScheduleOfChangesInFairValueOfPlanAssetsTableTextBlock |
| Examples of this text block disclosure: | ChangesInFairValueOfPlanAssets |
| Label | Role | Language |
| Schedule of Changes in Fair Value of Plan Assets [Table Text Block] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 715 20 50 1 (b) | http://fasb.org/us-gaap/role/ref/legacyRef | 715 |