XML 69 R63.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Derivatives and Other Financial Instruments - Schedule of Outstanding Forward Contracts that were Entered into Hedge Forecasted Transactions (Detail) (USD $) In Millions, unless otherwise specified | Mar. 31, 2014 t | Dec. 31, 2013 t
--- | --- | ---
Aluminum Contracts [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Aluminum contracts (000 metric tons) | 742,000 | 841,000
Energy Contracts [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Electricity (megawatt hours) | 59,409,328 | 59,409,328
Natural gas (million British thermal units) | 20,440,000 | 19,980,000
Foreign Exchange Contracts [Member] |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Foreign exchange contracts | $ 308 | $ 335

X
- Definition Outstanding forward contracts entered into as hedge forecasted transactions, foreign exchange contracts. + References No definition available. + Details
Name: | aa_OutstandingForwardContractsEnteredIntoAsHedgeForecastedTransactionsForeignExchangeContracts
Namespace Prefix: | aa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Outstanding forward contracts entered into as hedge forecasted transactions measured in British thermal units. + References No definition available. + Details
Name: | aa_Outstandingforwardcontractsenteredintoashedgeforecastedtransactionsmeasuredinbritishthermalunits
Namespace Prefix: | aa_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Outstanding forward contracts entered into as hedge forecasted transactions measured in mega watt hours. + References No definition available. + Details
Name: | aa_OutstandingForwardContractsEnteredIntoAsHedgeForecastedTransactionsMeasuredInMegaWattHours
Namespace Prefix: | aa_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Outstanding forward contracts entered into as hedging forecasted transactions measured in kilo metric ton. + References No definition available. + Details
Name: | aa_OutstandingForwardContractsEnteredIntoAsHedgingForecastedTransactionsMeasuredInKiloMetricTon
Namespace Prefix: | aa_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

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