cm:Concept: us-gaap:BusinessCombinationStepAcquisitionEquityInterestInAcquireeDescription
| Business Combination, Step Acquisition, Equity Interest in Acquiree, Description |
| us-gaap:BusinessCombinationStepAcquisitionEquityInterestInAcquireeDescription |
| In a business combination achieved in stages, this element represents a narrative description of the history, developments, or effect of the acquisition relative to the percentage of equity in the acquiree held by the acquirer immediately before the acquisition date. Such description may describe any gain recognized as a result of the acquisition. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:BusinessCombinationStepAcquisitionEquityInterestInAcquireeDescription |