| Standard label: | Fair Value, Inputs, Level 2 [Member] |
| Name: | us-gaap:FairValueInputsLevel2Member |
| Documentation: | Inputs other than quoted prices included within level 1 that are observable for an asset or liability, either directly or indirectly, including, but not limited to, quoted prices for similar assets or liabilities in active markets, or quoted prices for identical or similar assets or liabilities in inactive markets. |
| Object type: | cm:Member |
| Data type: | [Member] (nonnum:domainItemType) |
| Period type: | For Period (duration) |
| Balance type: | (no balance type) |
| Abstract: | true |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:FairValueInputsLevel2Member |
| Label | Role | Language |
| Fair Value, Inputs, Level 2 [Member] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 715 20 50 1 (d)(ii) | http://www.xbrl.org/2003/role/exampleRef | 715 |
| FASB Accounting Standards Codification 715 20 50 1 (d)(iv)(01) | http://www.xbrl.org/2003/role/disclosureRef | 715 |
| FASB Accounting Standards Codification 715 20 50 1 (d)(iv)(01) | http://www.xbrl.org/2003/role/exampleRef | 715 |
| FASB Accounting Standards Codification 715 20 55 17 | http://www.xbrl.org/2003/role/exampleRef | 715 |
| FASB Accounting Standards Codification 820 10 50 2 (b) | http://www.xbrl.org/2003/role/disclosureRef | 820 |
| FASB Accounting Standards Codification 860 20 50 3 (bb)(2) | http://www.xbrl.org/2003/role/disclosureRef | 860 |