| Standard label: | Fair Value, Recurring Basis, Unobservable Input Reconciliation, Asset (Liability), Gain (Loss), OCI |
| Name: | us-gaap:FairValueRecurringBasisUnobservableInputReconciliationAssetLiabilityGainLossOci |
| Documentation: | Amount of gain (loss) recognized in other comprehensive income (OCI) from asset (liability) measured at fair value on recurring basis using unobservable input (level 3). |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | For Period (duration) |
| Balance type: | Credit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:FairValueRecurringBasisUnobservableInputReconciliationAssetLiabilityGainLossOci |
| Label | Role | Language |
| Fair Value, Recurring Basis, Unobservable Input Reconciliation, Asset (Liability), Gain (Loss), OCI | http://www.xbrl.org/2003/role/label | en-US |
| Fair Value, Recurring Basis, Unobservable Input Reconciliation, Asset (Liability), Gain (Loss), OCI, Total | http://www.xbrl.org/2003/role/totalLabel | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 820 10 50 2 (c)(1a) | http://www.xbrl.org/2003/role/disclosureRef | 820 |