cm:Level3TextBlock: us-gaap:ScheduleOfRealEstatePropertiesTableTextBlock
| Schedule of Real Estate Properties [Table Text Block] |
| us-gaap:ScheduleOfRealEstatePropertiesTableTextBlock |
| Tabular disclosure of real estate properties and units in those properties that are included in the discussion of the nature of an entity's operations. |
| cm:Level3TextBlock |
| Text Block (HTML) (nonnum:textBlockItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:ScheduleOfRealEstatePropertiesTableTextBlock |
| RealEstateProperties |