cm:Concept: us-gaap:PrescriptionDrugBenefitSubsidyEffectNotDetermined
| Defined Benefit Plan, Prescription Drug Benefit Subsidy, Effect Not Determined [true false] |
| us-gaap:PrescriptionDrugBenefitSubsidyEffectNotDetermined |
| Indicates (true false) whether Medicare Prescription Drug, Improvement, and Modernization Act exists and accumulated postretirement benefit obligation or net periodic postretirement benefit cost (credit) does not reflect amount associated with government subsidy for prescription drug benefit because employer is unable to conclude whether benefit provided by plan is actuarially equivalent to Medicare Part D under Act. |
| cm:Concept |
| Yes/No (xbrli:booleanItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:PrescriptionDrugBenefitSubsidyEffectNotDetermined |