cm:Level2TextBlock: us-gaap:RevenueRecognitionInterest
| Revenue Recognition, Interest [Policy Text Block] |
| us-gaap:RevenueRecognitionInterest |
| Disclosure of accounting policy for recognition of interest revenue. Disclosure may include the method of recognizing interest income on loan and trade receivables, the method of amortizing premiums or accreting discounts, and a statement about the policy for the treatment of related fees and costs, including the method of amortizing net deferred fees and costs. |
| cm:Level2TextBlock |
| Text Block (HTML) (nonnum:textBlockItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:RevenueRecognitionInterest |