cm:Member: us-gaap:ExchangeOfProductHeldForSaleForDissimilarProductMember
| Exchange of Product Held-for-sale for Dissimilar Product [Member] |
| us-gaap:ExchangeOfProductHeldForSaleForDissimilarProductMember |
| The exchange of a product held for sale in the ordinary course of business for dissimilar property as a means of selling the product to a customer. |
| cm:Member |
| [Member] (nonnum:domainItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:ExchangeOfProductHeldForSaleForDissimilarProductMember |