XML 18 R56.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Forward delivery contracts and financial instruments (Details) | 9 Months Ended |  |  |  |
--- | --- | --- | --- | --- | ---
Sep. 30, 2013 Primary Aluminum Sales Contracts [Member] Glencore Metal Agreement [Member] t | Sep. 30, 2013 Primary Aluminum Sales Contracts [Member] Glencore Sweep Agreement [Member] | Sep. 30, 2013 Primary Aluminum Sales Contracts [Member] Glencore Nordural Metal Agreement [Member] t | Sep. 30, 2013 Primary Aluminum Sales Contracts [Member] Southwire Metal Agreement [Member] lb | Sep. 30, 2013 Primary Aluminum Sales Contracts [Member] RTA Metal Agreement [Member] t | Sep. 30, 2013 Long-Term Tolling Conctracts [Member] Billiton Tolling Agreement [Member] t | Sep. 30, 2013 Long-Term Tolling Conctracts [Member] Glencore Toll Agreement 1 [Member] t | Sep. 30, 2013 Long-Term Tolling Conctracts [Member] Glencore Toll Agreement 2 [Member] t | Sep. 30, 2013 Other Forward Delivery Contracts [Member] t | Dec. 31, 2012 Other Forward Delivery Contracts [Member] t | Sep. 30, 2013 Glencore [Member] Other Forward Delivery Contracts [Member] t | Dec. 31, 2012 Glencore [Member] Other Forward Delivery Contracts [Member] t
Supply Commitment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Customer | Glencore | [1] | Glencore | [2] | Glencore | Southwire | [3] | Rio Tinto Alcan | BHP Billiton | [4] | Glencore | [4] | Glencore | [4] |  |  |  |
Sales Volume Description | 20,400 metric tons per year ("mtpy") | [1] | Surplus primary aluminum produced in the United States | [2] | Approximately 19,000 metric tons | 220 to 240 million pounds per year (high conductivity molten aluminum) | [3] | Approximately 111,000 metric tons | 130,000 mtpy | [4] | 90,000 mtpy | [4] | 40,000 mtpy | [4] |  |  |  |
Volume maximum (in mtpy, metric tons, and pounds per year) | 20,400 | [1] |  |  | 19,000 | 240,000 | [3] | 111,000 | 130,000 | [4] | 90,000 | [4] | 40,000 | [4] |  |  |  |
Volume minimum (in mtpy, metric tons, and pounds per year) |  |  |  |  |  | 220,000 | [3] |  |  |  |  |  |  |  |  |  |  |
Term | Through December 31, 2013 | [1] | Through December 31, 2013 | [2] | Through December 31, 2013 | Through December 31, 2013 | [3] | Through December 31, 2013 | Through December 31, 2013 | [4] | Through July 31, 2016 | [4] | Through December 31, 2014 | [4] |  |  |  |
Pricing | Variable, based on U.S. Midwest market | [1] | Variable, based on U.S. Midwest market | [2] | Variable, based on LME | Variable, based on U.S. Midwest market | [3] | Variable, based on U.S. Midwest market | LME-based | [4] | LME-based | [4] | LME-based | [4] |  |  |  |
Other forward delivery contracts to sell primary aluminum (in metric tons) |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 32,994 | 88,827 | 1,775 | 1,811
[1] | We account for the Glencore Metal Agreement as a derivative instrument under ASC 815. Under the Glencore Metal Agreement, pricing is based on then-current Midwest market prices, adjusted by a negotiated U.S. Midwest premium with a cap and a floor as applied to the current U.S. Midwest premium.
[2] | The Glencore Sweep Agreement is for all metal produced in the U.S. in 2013, less existing sales agreements and high-purity metal sales. The term of the contract may be extended for one year upon mutual agreement.
[3] | The Southwire Metal Agreement contains termination rights in the event of a partial or full curtailment of the Hawesville facility. Despite reaching power agreements, certain regulatory approvals have not yet been received and CAKY could curtail all smelter operations if these approvals are not ultimately received.
[4] | Grundartangi’s tolling revenues include a premium based on the European Union (“EU”) import duty for primary aluminum.

X
- Definition Annual Primary Aluminum Physical Delivery Contract (Maximum) + References No definition available. + Details
Name: | cenx_AnnualPrimaryAluminumPhysicalDeliveryContract_Maximum
Namespace Prefix: | cenx_
Data Type: | num:massItemType
Balance Type: | na
Period Type: | duration

X
- Definition Annual Primary Aluminum Physical Delivery Contract (Minimum) + References No definition available. + Details
Name: | cenx_AnnualPrimaryAluminumPhysicalDeliveryContract_Minimum
Namespace Prefix: | cenx_
Data Type: | num:massItemType
Balance Type: | na
Period Type: | duration

X
- Definition Long Term Contract For Purchase Of Primary Aluminum, Contract Expiration Date + References No definition available. + Details
Name: | cenx_LongTermContractForPurchaseOfPrimaryAluminumContractExpirationDate
Namespace Prefix: | cenx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The description of the pricing terms for long term sales contracts. + References No definition available. + Details
Name: | cenx_LongTermSalesContractPricingDescription
Namespace Prefix: | cenx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The name of a particular customer for a company. + References No definition available. + Details
Name: | cenx_NameOfCustomer
Namespace Prefix: | cenx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Total amount of primary aluminum committed to be supplied under existing contracts or agreements outside of major long-term supply commitments. + References No definition available. + Details
Name: | cenx_OtherPrimaryAluminumDeliveryCommitmentsAndContractsVolume
Namespace Prefix: | cenx_
Data Type: | num:massItemType
Balance Type: | na
Period Type: | instant

X
- Definition Description of the particular sales volume for a particular customer. + References No definition available. + Details
Name: | cenx_SalesVolumeDescription
Namespace Prefix: | cenx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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