cm:Concept: us-gaap:IncreaseDecreaseInIncomeTaxes
| Increase (Decrease) in Income Taxes |
| us-gaap:IncreaseDecreaseInIncomeTaxes |
| The increase (decrease) during the reporting period in the amounts payable to taxing authorities for taxes that are based on the reporting entity's earnings, net of amounts receivable from taxing authorities for refunds of overpayments or recoveries of income taxes, and in deferred and other tax liabilities and assets. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Debit |
| false |
| us-gaap:IncreaseDecreaseInIncomeTaxes |