XML 101 R65.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Derivatives and Other Financial Instruments - Schedule of Carrying Values and Fair Values of Other Financial Instruments (Detail) (USD $) In Millions, unless otherwise specified | Jun. 30, 2013 | Dec. 31, 2012
--- | --- | ---
Cash and Cash Equivalents [Member] |  |
Derivative [Line Items] |  |
Carrying value | $ 1,202 | $ 1,861
Fair value | 1,202 | 1,861
Restricted Cash [Member] |  |
Derivative [Line Items] |  |
Carrying value | 84 | 189
Fair value | 84 | 189
Noncurrent Receivables [Member] |  |
Derivative [Line Items] |  |
Carrying value | 20 | 20
Fair value | 20 | 20
Available-for-Sale Securities [Member] |  |
Derivative [Line Items] |  |
Carrying value | 94 | 67
Fair value | 94 | 67
Short-Term Borrowings [Member] |  |
Derivative [Line Items] |  |
Carrying value | 55 | 53
Fair value | 55 | 53
Commercial Paper [Member] |  |
Derivative [Line Items] |  |
Carrying value |  |
Fair value |  |
Long-Term Debt Due within One Year [Member] |  |
Derivative [Line Items] |  |
Carrying value | 604 | 465
Fair value | 773 | 477
Long-Term Debt, Less Amount Due within One Year [Member] |  |
Derivative [Line Items] |  |
Carrying value | 7,700 | 8,311
Fair value | $ 7,730 | $ 9,028

X
- Definition Financial instruments owned at carrying value. + References No definition available. + Details
Name: | aa_FinancialInstrumentsOwnedAtCarryingValue
Namespace Prefix: | aa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Definition The aggregate fair value as of the balance sheet date of financial instruments and other positions owned by the entity including: (1) mortgages, mortgage-backed and asset backed securities; (2) US government and agency obligations; (3) state and municipal government obligations; (4) other sovereign government debt; (5) corporate obligations; (6) corporate equities; (7) principal investments; (8) derivative contracts; and (9) physical commodities. Includes both pledged and unpledged holdings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 940 -SubTopic 320 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=29643736&loc=d3e42546-110969 + Details
Name: | us-gaap_FinancialInstrumentsOwnedAtFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant