| Standard label: | Inventory, Policy [Policy Text Block] |
| Name: | us-gaap:InventoryPolicyTextBlock |
| Documentation: | Disclosure of inventory accounting policy for inventory classes, including, but not limited to, basis for determining inventory amounts, methods by which amounts are added and removed from inventory classes, loss recognition on impairment of inventories, and situations in which inventories are stated above cost. |
| 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:InventoryPolicyTextBlock |
| Label | Role | Language |
| Inventory, Policy [Policy Text Block] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 210 10 S99 1 (SX 210.5-02.6(b)) | http://fasb.org/us-gaap/role/ref/legacyRef | 210 |
| FASB Accounting Standards Codification 210 10 50 1 | http://fasb.org/us-gaap/role/ref/legacyRef | 210 |
| FASB Accounting Standards Codification 235 10 50 3 | http://fasb.org/us-gaap/role/ref/legacyRef | 235 |
| FASB Accounting Standards Codification 270 10 45 6 (a) | http://www.xbrl.org/2003/role/disclosureRef | 270 |
| FASB Accounting Standards Codification 330 10 50 1 | http://fasb.org/us-gaap/role/ref/legacyRef | 330 |
| FASB Accounting Standards Codification 330 10 50 4 | http://fasb.org/us-gaap/role/ref/legacyRef | 330 |