Statement of Consolidated Operations (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Sales (I)	$ 5,819	$ 5,454
Cost of goods sold (exclusive of expenses below)	4,443	4,495
Selling, general administrative, and other expenses	232	236
Research and development expenses	55	51
Provision for depreciation, depletion, and amortization	321	340
Restructuring and other charges (D)	177	461
Interest expense	122	120
Other (income) expenses, net (H)	(12)	25
Total costs and expenses	5,338	5,728
Income (loss) before income taxes	481	(274)
Provision (benefit) for income taxes (K)	226	(77)
Net income (loss)	255	(197)
Less: Net income (loss) attributable to noncontrolling interests	60	(19)
Net income (loss) attributable to Alcoa	$ 195	$ (178)
EARNINGS PER SHARE ATTRIBUTABLE TO ALCOA COMMON SHAREHOLDERS (J):
Basic	$ 0.15	$ (0.16)
Diluted	$ 0.14	$ (0.16)
Dividends paid per common share	$ 0.03	$ 0.03