cm:Level2TextBlock: us-gaap:RevenueTransactionPriceMeasurementTaxExclusionPolicyTextBlock
| Revenue, Transaction Price Measurement, Tax Exclusion [Policy Text Block] |
| us-gaap:RevenueTransactionPriceMeasurementTaxExclusionPolicyTextBlock |
| Disclosure of accounting policy for election to exclude from measurement of transaction price tax assessed by governmental authority that are both imposed on and concurrent with specific revenue-producing transaction, and collected from customer. Includes, but is not limited to, sales, use, value-added and excise tax. |
| cm:Level2TextBlock |
| Text Block (HTML) (nonnum:textBlockItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:RevenueTransactionPriceMeasurementTaxExclusionPolicyTextBlock |