| Standard label: | Fair Value Option, Disclosures [Table Text Block] |
| Name: | us-gaap:FairValueOptionQuantitativeDisclosuresTextBlock |
| Documentation: | Tabular disclosure of information about asset and liability measured at fair value under fair value option. |
| 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:FairValueOptionQuantitativeDisclosuresTextBlock |
| Label | Role | Language |
| Fair Value Option, Disclosures [Table Text Block] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 825 10 50 28 | http://www.xbrl.org/2009/role/commonPracticeRef | 825 |
| FASB Accounting Standards Codification 825 10 50 30 | http://fasb.org/us-gaap/role/ref/legacyRef | 825 |
| FASB Accounting Standards Codification 825 10 50 31 | http://www.xbrl.org/2009/role/commonPracticeRef | 825 |
| FASB Accounting Standards Codification 825 10 50 32 | http://www.xbrl.org/2009/role/commonPracticeRef | 825 |