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Quarterly Data - Schedule of Quarterly Data (Parenthetical) (Detail) (USD $)	3 Months Ended			12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2013
Income Statement [Abstract]
Loss from divestitures before income tax	$ 332,000,000us-gaap_DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax
Net loss , after tax and noncontrolling interest	163,000,000us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax
Goodwill impairment		1,731,000,000us-gaap_GoodwillImpairmentLoss		1,731,000,000us-gaap_GoodwillImpairmentLoss
Goodwill impairment after noncontrolling interest		1,719,000,000aa_GoodwillImpairmentLossAttributableToParent
Discrete income tax charge		372,000,000aa_DiscreteIncomeTaxExpense
Charges recorded of settlement amount		288,000,000us-gaap_LitigationSettlementExpense	0us-gaap_LitigationSettlementExpense
After-tax and noncontrolling interest		$ 243aa_LegalChargesAfterTaxAndNoncontrollingInterest

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Amount of gain (loss), before tax expense or benefit and not previously recognized, resulting from the sale of a business component.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 20

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Amount of gain (loss), after tax expense or benefit and not previously recognized, resulting from the sale of a business component.

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Amount of loss from the write-down 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.

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Amount of litigation expense, including but not limited to legal, forensic, accounting, and investigative fees.

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