XML 14 R54.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Commitments and contingencies (Details) (USD $) In Thousands, unless otherwise specified | 6 Months Ended | 156 Months Ended |  |  | 15 Months Ended | 45 Months Ended | 6 Months Ended | 1 Months Ended | 6 Months Ended
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Jun. 30, 2014 | Jun. 30, 2014 | Dec. 31, 2013 | Dec. 31, 2011 MW | Jun. 30, 2014 PBGC Agreement [Member] | Dec. 31, 2016 PBGC Forecast [Member] PBGC Agreement [Member] | Jun. 30, 2014 St. Croix Alumina Refinery [Member] | Apr. 30, 2013 Grundartangi Power Agreement [Member] | Jun. 30, 2014 Grundartangi OR Power Agreement [Member]
Environmental Contingencies [Abstract] |  |  |  |  |  |  |  |  |
Environmental-related accrued liabilities | $ 1,228 | $ 1,228 | $ 999 |  |  |  |  |  |
Environmental remediation expense minimum amount entitling reimbursement by third party | 400 |  |  |  |  |  |  |  |
Environmental remediation expense for Hydrocarbon Recovery Plan |  | 1,033 |  |  |  |  |  |  |
Legal Contingencies [Abstract] |  |  |  |  |  |  |  |  |
Legal settlement award payment |  |  |  |  |  |  | 625 | 1,470 | 3,600
PBCG Settlement [Abstract] |  |  |  |  |  |  |  |  |
Pension contributions above required minimum, total |  |  |  |  |  | 17,400 |  |  |
Pension contributions |  |  |  |  | 6,700 |  |  |  |
OR Power Agreement [Abstract] |  |  |  |  |  |  |  |  |
Power currently available under the power purchase agreement (in megawatts) |  |  |  | 47.5 |  |  |  |  |
Power prepayments | $ 2,000 | $ 2,000 |  |  |  |  |  |  |
Labor Commitments [Abstract] |  |  |  |  |  |  |  |  |
Percentage of U.S. based work force represented by a union (in hundredths) | 73.00% | 73.00% |  |  |  |  |  |  |
Number of labor unions Grundartangi subsidiary entered into a new labor agreement with | 5 | 5 |  |  |  |  |  |  |
Percentage of Grundartangi work force represented by the labor unions (in hundredths) | 82.00% | 82.00% |  |  |  |  |  |  |
Percentage of Vlissingen work force represented by the labor union (in hundredths) | 77.00% | 77.00% |  |  |  |  |  |  |

X
- Details
Name: | cenx_BigRiversAgreementAbstract
Namespace Prefix: | cenx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The minimum amount of environmental remediation expenses that must occur before entitlement to third party reimbursement. + References No definition available. + Details
Name: | cenx_EnvironmentalRemediationExpenseMinimumAmountEntitlingReimbursementByThirdParty
Namespace Prefix: | cenx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | cenx_LaborCommitmentsAbstract
Namespace Prefix: | cenx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | cenx_LegalContingenciesAbstract
Namespace Prefix: | cenx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of labor unions representing a group of employees. + References No definition available. + Details
Name: | cenx_NumberOfLaborUnionsUnderNewLaborAgreement
Namespace Prefix: | cenx_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Pursuant to the terms of the settlement agreement with the Pension Benefit Guaranty Corporation, we will make additional contributions (above any minimum required contributions) to our defined benefit pension plans. + References No definition available. + Details
Name: | cenx_PensionContributionsAboveRequiredMinimumTotal
Namespace Prefix: | cenx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The percentage of a Company's work force, based in the country of domicile, that are subject to collective bargaining agreements. + References No definition available. + Details
Name: | cenx_PercentageOfDomesticWorkForceInUnion
Namespace Prefix: | cenx_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The percentage of a Company's Netherlands work force that are subject to collective bargaining agreements + References No definition available. + Details
Name: | cenx_PercentageofforeignNetherlandsworkforcerepresentedbythelaborunioninhundredths
Namespace Prefix: | cenx_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The percentage of a Company's Icelandic work force that are subject to collective bargaining agreements. + References No definition available. + Details
Name: | cenx_PercentageOfForeignWorkForceCoveredUnderNewLaborAgreement
Namespace Prefix: | cenx_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The power currently available under the power purchase agreement. + References No definition available. + Details
Name: | cenx_PowerAvailable
Namespace Prefix: | cenx_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | cenx_RavenswoodPensionPlanAbstract
Namespace Prefix: | cenx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Total costs accrued as of the balance sheet date for environmental loss contingencies. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 30 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13207-110859 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 25 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6395460&loc=d3e13647-108346 + Details
Name: | us-gaap_AccrualForEnvironmentalLossContingencies
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The charge against earnings in the period for known or estimated future costs arising from requirements to perform environmental remediation activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 30 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13296-110859 + Details
Name: | us-gaap_EnvironmentalRemediationExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

X
- Definition Amount of judgment or settlement awarded to (against) the entity in respect of litigation. + References No definition available. + Details
Name: | us-gaap_LitigationSettlementAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of cash or cash equivalents contributed by the entity to fund its pension plans. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 25 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3536-108585 + Details
Name: | us-gaap_PensionContributions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Sum of the carrying amounts as of the balance sheet date of amounts paid in advance for expenses which will be charged against earnings in periods after one year or beyond the operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 17 -Article 5 + Details
Name: | us-gaap_PrepaidExpenseNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant