cm:Concept: us-gaap:NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOnFinancialStatementsFlag
| Change in Accounting Principle, Effect on Financial Statement [Fixed List] |
| us-gaap:NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOnFinancialStatementsFlag |
| Indicates whether change in accounting principle is expected to have significant effect on financial statement. Acceptable values are "Yes" and "No". |
| cm:Concept |
| Yes/No (us-types:yesNoItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOnFinancialStatementsFlag |