Statement of Consolidated Operations (unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
Sales (K)	$ 5,295	$ 5,897	$ 10,242	$ 11,716
Cost of goods sold (exclusive of expenses below)	4,216	4,663	8,257	9,106
Selling, general administrative, and other expenses (P)	286	224	546	456
Research and development expenses	39	68	81	123
Provision for depreciation, depletion, and amortization	309	319	618	640
Restructuring and other charges (D)	23	217	116	394
Interest expense	129	124	256	246
Other income, net (J)	(37)		(3)	(12)
Total costs and expenses	4,965	5,615	9,871	10,953
Income before income taxes	330	282	371	763
Provision for income taxes	152	75	182	301
Net income	178	207	189	462
Less: Net income attributable to noncontrolling interests	43	67	38	127
Consolidated net income attributable to Alcoa	135	140	151	335
AMOUNTS ATTRIBUTABLE TO ALCOA COMMON SHAREHOLDERS (L):
Net income	$ 118	$ 123	$ 116	$ 300
Earnings per share:
Basic	$ 0.09	$ 0.10	$ 0.09	$ 0.25
Diluted	0.09	0.10	0.09	0.24
Dividends paid per share	$ 0.03	$ 0.03	$ 0.06	$ 0.06