cm:Concept: us-gaap:ProFormaWeightedAverageSharesOutstandingDiluted
| Pro Forma Weighted Average Shares Outstanding, Diluted |
| us-gaap:ProFormaWeightedAverageSharesOutstandingDiluted |
| The weighted average number of shares or units and dilutive common stock or unit equivalents outstanding in the calculation of proforma diluted earnings per share (earnings per unit), which is commonly presented in initial public offerings based on the terms of the offering. |
| cm:Concept |
| Shares (xbrli:sharesItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:ProFormaWeightedAverageSharesOutstandingDiluted |