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Forward delivery contracts and financial instruments (Details) | 3 Months Ended |  |  |  |
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Mar. 31, 2014 Primary Aluminum Sales Contracts [Member] Glencore Nordural Metal Agreement [Member] t | Mar. 31, 2014 Primary Aluminum Sales Contracts [Member] Southwire Metal Agreement [Member] lb | Mar. 31, 2014 Long-Term Tolling Conctracts [Member] Glencore Toll Agreement 1 [Member] t | Mar. 31, 2014 Long-Term Tolling Conctracts [Member] Glencore Toll Agreement 2 [Member] t | Mar. 31, 2014 Other Forward Delivery Contracts [Member] t | Dec. 31, 2013 Other Forward Delivery Contracts [Member] t | Mar. 31, 2014 Glencore [Member] Other Forward Delivery Contracts [Member] t | Dec. 31, 2013 Glencore [Member] Other Forward Delivery Contracts [Member] t
Supply Commitment [Line Items] |  |  |  |  |  |  |  |  |  |
Customer | Glencore | [1] | Southwire | [2] | Glencore | Glencore |  |  |  |
Volume | All primary aluminum produced at Grundartangi, net of tolling and other sales commitments | [1] | 216 million pounds per year (high conductivity molten aluminum) | [2] | 90,000 tonnes per year ("tpy") | 49,000 tpy |  |  |  |
Volume (in tpy and lbs per year) | 155,000 |  | 216,000,000 |  | 90,000 | 49,000 |  |  |  |
Volume adjustment (in percent) |  |  | 4.00% |  |  |  |  |  |  |
Term | January 1, 2014 through December 31, 2017 | [1] | January 1, 2014 through December 31, 2014 | [2] | Through July 2016 | Through December 31, 2014 |  |  |  |
Pricing | Variable, based on LME and European Duty Paid premium | [1] | Variable, based on U.S. Midwest Transaction Price | [2] | Variable, based on LME and European Duty Paid premium | Variable, based on LME and European Duty Paid premium |  |  |  |
Other forward delivery contracts to sell primary aluminum (in tonnes) |  |  |  |  |  |  | 101,649 | 118,373 | 23,692 | 20,008
Other forward delivery contracts to sell primary aluminum at fixed price (in tonnes) |  |  |  |  |  |  | 52 | 0 |  |
[1] | The Glencore Grundartangi Metal Agreement is for all metal produced at Grundartangi from 2014 through 2017 less commitments under existing tolling and other sales contracts. Grundartangi currently estimates that it will sell Glencore approximately 155,000 tonnes of aluminum under this agreement in 2014.
[2] | Southwire may, at its option, increase the volume purchased under the agreement by up to four percent by adjusting their monthly metal commitment.

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- Definition Annual Primary Aluminum Physical Delivery Contract (Maximum) + References No definition available. + Details
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- Definition The percentage by which the monthly commitment can be adjustment, per the contract. + References No definition available. + Details
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- Definition Long Term Contract For Purchase Of Primary Aluminum, Contract Expiration Date + References No definition available. + Details
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- 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
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- Definition The fixed price commitments for delivery of primary aluminum on forward delivery contracts. + References No definition available. + Details
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- Definition Description of the particular sales volume for a particular customer. + References No definition available. + Details
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- Details
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