cm:Level3TextBlock: us-gaap:ScheduleOfStockholdersEquityTableTextBlock
| Schedule of Stockholders Equity [Table Text Block] |
| us-gaap:ScheduleOfStockholdersEquityTableTextBlock |
| Tabular disclosure of changes in the separate accounts comprising stockholders' equity (in addition to retained earnings) and of the changes in the number of shares of equity securities during at least the most recent annual fiscal period and any subsequent interim period presented is required to make the financial statements sufficiently informative if both financial position and results of operations are presented. |
| cm:Level3TextBlock |
| Text Block (HTML) (nonnum:textBlockItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:ScheduleOfStockholdersEquityTableTextBlock |
| StockholdersEquity |