XML 81 R57.htm IDEA: XBRL DOCUMENT v2.3.0.15

Accounts Receivables (Details) (USD $) In Millions	Sep. 30, 2011
Accounts Receivables
Sold receivables that remain uncollected	$ 206

X

- Definition

Amount Of Sold Receivables Remain Uncollected

+ Details

Name:	aa_AmountOfSoldReceivablesRemainUncollected
Namespace Prefix:	aa
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	us-gaap_TransfersAndServicingAbstract
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration