| Standard label: | Share-based Payment Arrangement, Option, Exercise Price Range [Table Text Block] |
| Name: | us-gaap:ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTextBlock |
| Documentation: | Tabular disclosure of option exercise prices, by grouped ranges, including the upper and lower limits of the price range, the number of shares under option, weighted average exercise price and remaining contractual option terms. |
| 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:ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTextBlock |
| Examples of this text block disclosure: | SharebasedCompensationSharesAuthorizedunderStockOptionPlansByExercisePriceRange |
| Label | Role | Language |
| Share-based Payment Arrangement, Option, Exercise Price Range [Table Text Block] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 718 10 50 2 | http://fasb.org/us-gaap/role/ref/legacyRef | 718 |