cm:Concept: us-gaap:WeightedAverageBasicSharesOutstandingProForma
| Weighted Average Basic Shares Outstanding, Pro Forma |
| us-gaap:WeightedAverageBasicSharesOutstandingProForma |
| The weighted average number of shares (units) outstanding in the calculation of pro forma basic 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:WeightedAverageBasicSharesOutstandingProForma |