cm:Concept: us-gaap:StockholdersEquityNoteChangesInCapitalStructureRetroactiveImpact
| Stockholders' Equity Note, Changes in Capital Structure, Retroactive Impact |
| us-gaap:StockholdersEquityNoteChangesInCapitalStructureRetroactiveImpact |
| Description of the total capital structure change due to a stock dividend, stock split and reserve split occurring after the balance sheet date but prior to the later of the issuance of financial statement or the effective date of registration statement. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:StockholdersEquityNoteChangesInCapitalStructureRetroactiveImpact |