XML 136 R150.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Subsequent Events (Details) (USD $) In Millions, unless otherwise specified | 1 Months Ended | 12 Months Ended
--- | --- | ---
Feb. 29, 2012 | Jan. 31, 2012 | Dec. 31, 2011
Subsequent Event [Line Items] |  |  |
Repaid outstanding principal |  | $ 322 |
Proceeds from term loan |  | 350 |
Interest rate on notes issued |  | 6.00% |
Revolving credit agreement, credit facility | 100 | 100 |
Revolving credit facility, expiration date |  |  | 2012
Defined Benefit Plan, Contribution To Pension Plan |  | 95 |
Amount borrowed under the credit facility | 100 |  |
Aluminio [Member] |  |  |
Subsequent Event [Line Items] |  |  |
Proceeds from term loan |  | $ 280 |
Weighted-average interest rate |  | 2.32% |
Debt instrument weighted-average maturity period, in days |  | 172 |
5.375% Notes, Due 2013 [Member] |  |  |
Subsequent Event [Line Items] |  |  |
Interest rate on notes issued |  |  | 5.375%
Debt instrument, maturity date |  |  | 2013
LIBOR Plus [Member] |  |  |
Subsequent Event [Line Items] |  |  |
LIBOR plus margin | 1.25% | 1.50% |
Term Loans [Member] |  |  |
Subsequent Event [Line Items] |  |  |
Debt instrument, maturity date |  | July 2012 |
Revolving Credit Facility [Member] |  |  |
Subsequent Event [Line Items] |  |  |
Debt instrument, maturity date |  |  | July 25, 2016
Revolving credit facility, expiration date |  | December 2012 |

X
- Definition Debt instruments maturity date. + References No definition available. + Details
Name: | aa_DebtInstrumentsMaturityDate
Namespace Prefix: | aa_
Data Type: | invest:dateStringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt instrument weighted-average maturity period. + References No definition available. + Details
Name: | aa_DebtInstrumentWeightedAverageMaturityPeriod
Namespace Prefix: | aa_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined Benefit Plan, Contribution To Pension Plan + References No definition available. + Details
Name: | aa_DefinedBenefitPlanContributionToPensionPlan
Namespace Prefix: | aa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentBasisSpreadOnVariableRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Interest rate stated in the contractual debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Reflects the calculation as of the balance sheet date of the average interest rate weighted by the amount of debt outstanding by type or by instrument at that time. + References No definition available. + Details
Name: | us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Reflects when the credit facility terminates, which may be presented in a variety of ways (year, month and year, day, month and year, quarter). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 129 -Paragraph 2, 4 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 22 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityExpirationDate
Namespace Prefix: | us-gaap_
Data Type: | us-types:dateStringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Increase for additional borrowings on the credit facility during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 4 -Section 08 -Paragraph f Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(f)) -URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690 + Details
Name: | us-gaap_LineOfCreditFacilityIncreaseAdditionalBorrowings
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 129 -Paragraph 2, 4 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 22 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The cash inflow from bank borrowing during the year. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3255-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 19 -Subparagraph b -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228 + Details
Name: | us-gaap_ProceedsFromBankDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations. + References No definition available. + Details
Name: | us-gaap_RepaymentsOfDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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