| Standard label: | Consolidation, Subsidiaries or Other Investments, Consolidated Entities, Policy [Policy Text Block] |
| Name: | us-gaap:ConsolidationSubsidiariesOrOtherInvestmentsConsolidatedEntitiesPolicy |
| Documentation: | Disclosure of accounting policy for subsidiaries or other investments that are consolidated, including the accounting treatment for intercompany accounts or transactions and any noncontrolling interest. |
| Object type: | cm:Level2TextBlock |
| 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:ConsolidationSubsidiariesOrOtherInvestmentsConsolidatedEntitiesPolicy |
| Label | Role | Language |
| Consolidation, Subsidiaries or Other Investments, Consolidated Entities, Policy [Policy Text Block] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 235 10 S99 1 (SX 210.4-08(a)) | http://www.xbrl.org/2003/role/disclosureRef | 235 |
| FASB Accounting Standards Codification 235 10 50 3 | http://fasb.org/us-gaap/role/ref/legacyRef | 235 |
| FASB Accounting Standards Codification 810 10 50 1 | http://www.xbrl.org/2003/role/disclosureRef | 810 |
| FASB Accounting Standards Codification 810 10 S99 2 (SX 210.3A-02) | http://www.xbrl.org/2003/role/disclosureRef | 810 |
| FASB Accounting Standards Codification 810 10 S99 3 (SX 210.3A-03) | http://www.xbrl.org/2003/role/disclosureRef | 810 |
| FASB Accounting Standards Codification 810 10 S99 4 (SX 210.3A-04) | http://www.xbrl.org/2003/role/disclosureRef | 810 |