cm:Concept: us-gaap:DebtInstrumentConvertibleIfConvertedValueInExcessOfPrincipal
| Debt Instrument, Convertible, If-converted Value in Excess of Principal |
| us-gaap:DebtInstrumentConvertibleIfConvertedValueInExcessOfPrincipal |
| The amount by which the convertible debt's if-converted value exceeds its principle amount at the balance sheet date, regardless of whether the instrument is currently convertible. This element applies to public companies only. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Credit |
| false |
| us-gaap:DebtInstrumentConvertibleIfConvertedValueInExcessOfPrincipal |