cm:Concept: us-gaap:EffectOfExchangeRateOnCashAndCashEquivalentsDiscontinuedOperations
| Effect of Exchange Rate on Cash and Cash Equivalents, Discontinued Operations |
| us-gaap:EffectOfExchangeRateOnCashAndCashEquivalentsDiscontinuedOperations |
| The effect of exchange rate changes on cash balances in discontinuing operations held in foreign currencies. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Debit |
| false |
| us-gaap:EffectOfExchangeRateOnCashAndCashEquivalentsDiscontinuedOperations |