XML 23 R54.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Summary of significant accounting policies Schedule of Property, Plant and Equipment (Details) | 12 Months Ended
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Dec. 31, 2014
Building and Building Improvements [Member] |
Property, Plant and Equipment [Line Items] |
Estimated useful life minimum (in years) | 10 cenx_EstimatedUsefulLifeMinimumInYears / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_BuildingAndBuildingImprovementsMember
Estimated useful life maximum (in years) | 45 cenx_EstimatedUsefulLifeMaximumInYears / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_BuildingAndBuildingImprovementsMember
Machinery and Equipment [Member] |
Property, Plant and Equipment [Line Items] |
Estimated useful life minimum (in years) | 5 cenx_EstimatedUsefulLifeMinimumInYears / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_MachineryAndEquipmentMember
Estimated useful life maximum (in years) | 35 cenx_EstimatedUsefulLifeMaximumInYears / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_MachineryAndEquipmentMember

X
- Definition The maximum useful life of long-lived, physical assets used in the normal conduct of business and not intended for resale. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software. + References No definition available. + Details
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Namespace Prefix: | cenx_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

X
- Definition The minimum useful life of long lived, physical assets used in the normal conduct of business and not intended for resale. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software. + References No definition available. + Details
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Namespace Prefix: | cenx_
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Balance Type: | na
Period Type: | duration

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- Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_BuildingAndBuildingImprovementsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_MachineryAndEquipmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |