Statement of Consolidated Operations (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Statement [Abstract]
Sales (H)	$ 5,849	$ 5,963	$ 11,682	$ 11,969
Cost of goods sold (exclusive of expenses below)	4,933	5,154	9,780	10,252
Selling, general administrative, and other expenses	254	245	505	486
Research and development expenses	46	47	91	90
Provision for depreciation, depletion, and amortization	362	363	723	732
Restructuring and other charges (C)	244	15	251	25
Interest expense	118	123	233	246
Other expenses (income), net (G)	19	22	(8)	6
Total costs and expenses	5,976	5,969	11,575	11,837
(Loss) income before income taxes	(127)	(6)	107	132
Provision for income taxes (J)	21	13	85	52
Net (loss) income	(148)	(19)	22	80
Less: Net loss attributable to noncontrolling interests	(29)	(17)	(8)	(12)
NET (LOSS) INCOME ATTRIBUTABLE TO ALCOA	$ (119)	$ (2)	$ 30	$ 92
EARNINGS PER SHARE ATTRIBUTABLE TO ALCOA COMMON SHAREHOLDERS (I):
Basic	$ (0.11)		$ 0.03	$ 0.09
Diluted	$ (0.11)		$ 0.03	$ 0.08
Dividends paid per common share	$ 0.03	$ 0.03	$ 0.06	$ 0.06