| Standard label: | Cash and Cash Equivalents, Policy [Policy Text Block] |
| Name: | us-gaap:CashAndCashEquivalentsPolicyTextBlock |
| Documentation: | Disclosure of accounting policy for cash and cash equivalents, including the policy for determining which items are treated as cash equivalents. Other information that may be disclosed includes (1) the nature of any restrictions on the entity's use of its cash and cash equivalents, (2) whether the entity's cash and cash equivalents are insured or expose the entity to credit risk, (3) the classification of any negative balance accounts (overdrafts), and (4) the carrying basis of cash equivalents (for example, at cost) and whether the carrying amount of cash equivalents approximates fair value. |
| 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:CashAndCashEquivalentsPolicyTextBlock |
| Label | Role | Language |
| Cash and Cash Equivalents, 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(1)) | http://fasb.org/us-gaap/role/ref/legacyRef | 210 |
| FASB Accounting Standards Codification 230 10 50 1 | http://fasb.org/us-gaap/role/ref/legacyRef | 230 |
| FASB Accounting Standards Codification 235 10 50 3 | http://fasb.org/us-gaap/role/ref/legacyRef | 235 |