cm:Concept: us-gaap:EnvironmentalExpenseAndLiabilities
| Environmental Expense and Liabilities |
| us-gaap:EnvironmentalExpenseAndLiabilities |
| The adjustment to exclude the noncash portion of, and include cash payments for environmental costs when calculating operating cash flows under the indirect method. The adjustment can include the increase (decrease) during an accounting period in total estimated obligations recorded for probable future loss attributable to environmental contamination issues. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Debit |
| false |
| us-gaap:EnvironmentalExpenseAndLiabilities |