| Standard label: | Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward] |
| Name: | us-gaap:DefinedBenefitPlanChangeInFairValueOfPlanAssetsLevel3ReconciliationRollForward |
| Documentation: | A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. |
| Object type: | cm:Abstract |
| Data type: | Text/String (xbrli:stringItemType) |
| Period type: | For Period (duration) |
| Balance type: | (no balance type) |
| Abstract: | true |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:DefinedBenefitPlanChangeInFairValueOfPlanAssetsLevel3ReconciliationRollForward |
| Label | Role | Language |
| Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |