cm:Concept: us-gaap:DebtInstrumentConvertibleThresholdTradingDays
| Debt Instrument, Convertible, Threshold Trading Days |
| us-gaap:DebtInstrumentConvertibleThresholdTradingDays |
| Threshold number of specified trading days that common stock price to conversion price of convertible debt instruments must exceed threshold percentage within a specified consecutive trading period to trigger conversion feature. |
| cm:Concept |
| Integer (xbrli:integerItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:DebtInstrumentConvertibleThresholdTradingDays |