cm:Concept: us-gaap:StockholdersEquityNoteChangesInCapitalStructureSubsequentChangesToNumberOfCommonShares
| Stockholders' Equity Note, Changes in Capital Structure, Subsequent Changes to Number of Common Shares |
| us-gaap:StockholdersEquityNoteChangesInCapitalStructureSubsequentChangesToNumberOfCommonShares |
| Change in number of shares issued and outstanding as a result of capital structure change to a stock dividend, stock split or reserve split occurring after the balance sheet date but prior to the later of the issuance of financial statements or the effective date of registration statement. |
| cm:Concept |
| Shares (xbrli:sharesItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:StockholdersEquityNoteChangesInCapitalStructureSubsequentChangesToNumberOfCommonShares |