| Standard label: | Schedule of Loss Contingencies by Contingency [Table Text Block] |
| Name: | us-gaap:ScheduleOfLossContingenciesByContingencyTextBlock |
| Documentation: | Tabular disclosure of the loss contingencies that were reported in the period or disclosed as of the balance sheet date. |
| 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:ScheduleOfLossContingenciesByContingencyTextBlock |
| Examples of this text block disclosure: | LossContingencies |
| Label | Role | Language |
| Schedule of Loss Contingencies by Contingency [Table Text Block] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 450 20 50 1 | http://fasb.org/us-gaap/role/ref/legacyRef | 450 |
| FASB Accounting Standards Codification 450 20 50 3 | http://fasb.org/us-gaap/role/ref/legacyRef | 450 |
| FASB Accounting Standards Codification 450 20 50 4 | http://fasb.org/us-gaap/role/ref/legacyRef | 450 |
| FASB Accounting Standards Codification 450 20 50 5 | http://fasb.org/us-gaap/role/ref/legacyRef | 450 |
| FASB Accounting Standards Codification 450 20 50 6 | http://fasb.org/us-gaap/role/ref/legacyRef | 450 |
| FASB Accounting Standards Codification 450 20 50 9 | http://fasb.org/us-gaap/role/ref/legacyRef | 450 |
| FASB Accounting Standards Codification 450 20 50 10 | http://fasb.org/us-gaap/role/ref/legacyRef | 450 |
| FASB Accounting Standards Codification 460 10 50 2 | http://fasb.org/us-gaap/role/ref/legacyRef | 460 |
| FASB Accounting Standards Codification 460 10 50 3 | http://fasb.org/us-gaap/role/ref/legacyRef | 460 |