XML 13 R54.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Subsequent events Agreement to purchase Sebree smelter (Details) (USD $) | Apr. 29, 2013 t
--- | ---
Subsequent Event [Line Items] |
Sebree Primary Aluminum Capacity | 205,000,000
Sebree Smelter [Member] |
Subsequent Event [Line Items] |
Entity Number of Employees | 500
Cash | 61,000
Assumed retiree medical obligations reduction in price | 4,000
Increase (Decrease) in Operating Capital | 71,000

X
- Definition purchase price reduction relating to certain assumed retiree medical obligations in the Century Sebree acquisition. + References No definition available. + Details
Name: | cenx_AssumedRetireeMedicalObligationsReductionInPrice
Namespace Prefix: | cenx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Sebree Primary Aluminum Capacity + References No definition available. + Details
Name: | cenx_SebreePrimaryAluminumCapacity
Namespace Prefix: | cenx_
Data Type: | num:massItemType
Balance Type: | na
Period Type: | instant

X
- Definition Represents operating liquidity available to a business, organization or other entity, including governmental entity. Along with fixed assets such as plant and equipment, working capital is considered a part of operating capital. Net working capital is calculated as current assets minus current liabilities + References No definition available. + Details
Name: | cenx_WorkingCapital
Namespace Prefix: | cenx_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of persons employed by the Entity + References No definition available. + Details
Name: | dei_EntityNumberOfEmployees
Namespace Prefix: | dei_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Excludes cash and cash equivalents within disposal group and discontinued operation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash -URI http://asc.fasb.org/extlink&oid=6506951 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.1) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
Name: | us-gaap_Cash
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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