cm:Level3TextBlock: us-gaap:ScheduleOfDeferredCompensationArrangementWithIndividualShareBasedPaymentsTextBlock
| Schedule of Deferred Compensation Arrangement with Individual, Share-based Payments [Table Text Block] |
| us-gaap:ScheduleOfDeferredCompensationArrangementWithIndividualShareBasedPaymentsTextBlock |
| Tabular disclosure of an equity-based arrangement (such as stock or unit options and stock or unit awards) with an individual employee, which is generally an employment contract between the entity and a selected officer or key employee containing a promise by the employer to pay certain equity-based awards at future dates, sometimes including a period after retirement, upon compliance with stipulated requirements. This type of arrangement is distinguished from broader based employee benefit plans as it is usually tailored to the employee. Disclosure also typically includes the amount of related compensation expense recognized during the reporting period, the number of shares or units issued during the period under such arrangements, and the carrying amount as of the balance sheet date of the related liability. |
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| DeferredCompensationArrangementWithIndividualSharebasedPayments |