cm:Concept: us-gaap:IncreaseDecreaseInAccountsAndNotesReceivable
| Increase (Decrease) in Accounts and Notes Receivable |
| us-gaap:IncreaseDecreaseInAccountsAndNotesReceivable |
| The increase (decrease) during the reporting period of the sum of amounts due within one year (or one business cycle) from customers for the credit sale of goods and services; and from note holders for outstanding loans. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Credit |
| false |
| us-gaap:IncreaseDecreaseInAccountsAndNotesReceivable |