XML 1054 R76.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Acquisitions and Divestitures - Additional Information (Detail) (USD $) In Millions, unless otherwise specified | 12 Months Ended |  |  | 12 Months Ended |  |  |  | 12 Months Ended
--- | --- | --- | --- | --- | --- | --- | --- | ---
Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011 | Dec. 31, 2013 Russia [Member] Facility | Dec. 31, 2011 TransDigm Group Inc [Member] Employees | Dec. 31, 2010 TransDigm Group Inc [Member] | Dec. 31, 2011 TransDigm Group Inc [Member] California [Member] Location | Dec. 31, 2011 TransDigm Group Inc [Member] United Kingdom [Member] Location | Dec. 31, 2013 Corporate [Member] | Dec. 31, 2012 Corporate [Member] | Dec. 31, 2011 Corporate [Member] | Dec. 31, 2012 351 - Megawatt Tapoco Hydroelectric Project [Member] acre ElectricStation mi | Dec. 31, 2012 351 - Megawatt Tapoco Hydroelectric Project [Member] Primary Metals Segment [Member] | Dec. 31, 2012 351 - Megawatt Tapoco Hydroelectric Project [Member] Corporate [Member]
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sale of energy |  |  |  |  |  |  |  |  |  |  |  | $ 597 |  |
Gain (loss) on sale of business |  |  |  |  |  |  |  |  |  |  |  | 320 | 426 | 106
Gain (loss) on sale of business, after tax |  |  |  |  |  |  |  |  |  |  |  | 173 | 275 | 102
Number of hydroelectric generating stations and dams |  |  |  |  |  |  |  |  |  |  |  | 4 |  |
Length of transmission line |  |  |  |  |  |  |  |  |  |  |  | 86 |  |
Acres of land associated with divestitures |  |  |  |  |  |  |  |  |  |  |  | 14,500 |  |
Allocation of goodwill |  |  |  |  |  |  |  |  |  |  |  | (94) |  |
Business acquisition cost |  |  |  |  | 240 |  |  |  |  |  |  |  |  |
Cash acquired and post-closing adjustments resulted in net purchase price |  |  |  |  | 239 |  |  |  |  |  |  |  |  |
Number of employees |  |  |  |  | 400 |  |  |  |  |  |  |  |  |
Number of business locations |  |  |  |  |  |  | 1 | 2 |  |  |  |  |  |
Sales generated in last annual period prior to divestiture |  |  |  |  |  | 61 |  |  |  |  |  |  |  |
Amount of goodwill recorded | 3,415 | 5,170 | 5,157 |  |  |  |  |  | 518 | 1,272 | 1,281 |  |  |
Reduction of initial goodwill amount | 1 |  |  |  |  |  |  |  |  |  |  |  |  |
Amount of goodwill is estimated to be deductible for income tax purposes | 60 |  |  |  |  |  |  |  |  |  |  |  |  |
Additional contingent consideration payable | $ 50 |  |  |  |  |  |  |  |  |  |  |  |  |
Number of facilities acquired |  |  |  | 2 |  |  |  |  |  |  |  |  |  |

X
- Definition Acres of land. + References No definition available. + Details
Name: | aa_AcresOfLand
Namespace Prefix: | aa_
Data Type: | num:areaItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of reduction in the initial goodwill amount. + References No definition available. + Details
Name: | aa_AmountOfReductionInInitialGoodwillAmount
Namespace Prefix: | aa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Business acquisition additional contingent consideration potential cash payment. + References No definition available. + Details
Name: | aa_BusinessAcquisitionAdditionalContingentConsiderationPotentialCashPayment
Namespace Prefix: | aa_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Cash acquired and post-closing adjustments resulted in net purchase price. + References No definition available. + Details
Name: | aa_CashAcquiredAndPostClosingAdjustmentsResultedInNetPurchasePrice
Namespace Prefix: | aa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Additional financial information of a disposal group, not classified as discontinued operations, from last annual period prior to divestiture, such as amount of sales , net income or loss, etc. + References No definition available. + Details
Name: | aa_DisposalGroupNotDiscontinuedOperationAdditionalInformation
Namespace Prefix: | aa_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Gain (loss) on sale of business net of tax. + References No definition available. + Details
Name: | aa_GainLossOnSaleOfBusinessNetOfTax
Namespace Prefix: | aa_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Length of transmission line. + References No definition available. + Details
Name: | aa_LengthOfTransmissionLine
Namespace Prefix: | aa_
Data Type: | num:lengthItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of employees. + References No definition available. + Details
Name: | aa_NumberOfEmployees
Namespace Prefix: | aa_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of facilities acquired. + References No definition available. + Details
Name: | aa_NumberOfFacilitiesAcquired
Namespace Prefix: | aa_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of hydroelectric generating stations and dams. + References No definition available. + Details
Name: | aa_NumberOfHydroelectricGeneratingStationsAndDams
Namespace Prefix: | aa_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of locations. + References No definition available. + Details
Name: | aa_NumberOfLocations
Namespace Prefix: | aa_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition The amount of goodwill arising from a business combination that is expected to be deductible for tax purposes. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=7488404&loc=d3e6927-128479 + Details
Name: | us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6578-128477 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6613-128477 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=7488404&loc=d3e6927-128479 + Details
Name: | us-gaap_BusinessCombinationConsiderationTransferred1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Gain (loss) from sale or disposal of an organization or integrated set of activities (for example, but not limited to, a partnership or corporation) engaged in providing a product or service in a commercial, industrial, or professional environment. + References No definition available. + Details
Name: | us-gaap_GainLossOnSaleOfBusiness
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266 + Details
Name: | us-gaap_Goodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 25 -Paragraph 16 -URI http://asc.fasb.org/extlink&oid=21917927&loc=d3e961-128460 + Details
Name: | us-gaap_GoodwillPurchaseAccountingAdjustments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Investing Activities -URI http://asc.fasb.org/extlink&oid=6516133 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3179-108585 + Details
Name: | us-gaap_ProceedsFromDivestitureOfBusinesses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration