Statement of Consolidated Operations (unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Sales (I)	$ 3,192	$ 3,055
Cost of goods sold (exclusive of expenses below)	2,492	2,400
Selling, general administrative, and other expenses	221	205
Research and development expenses	28	31
Provision for depreciation and amortization	133	133
Restructuring and other charges (D & E)	73	16
Interest expense	115	121
Other income, net (G)	(354)	(12)
Total costs and expenses	2,708	2,894
Income from continuing operations before income taxes	484	161
Provision for income taxes	162	51
Income from continuing operations after income taxes	322	110
Loss from discontinued operations after income taxes (G)		(99)
Net income	322	11
Less: Loss from discontinued operations attributable to noncontrolling interests (G)		(5)
Net income attributable to Arconic	322	16
Amounts Attributable to Arconic Common Shareholders (J):
Net income (loss)	$ 305	$ (2)
Earnings per share - basic
Continuing operations	$ 0.69	$ 0.21
Discontinued operations		(0.21)
Net income per share - basic	0.69	0.00
Earnings per share - diluted
Continuing operations	0.65	0.21
Discontinued operations		(0.21)
Net income per share - diluted	0.65	0.00
Dividends paid per share	$ 0.06	$ 0.09
Weighted Average Shares Outstanding (J):
Average shares outstanding - basic	440	438
Average shares outstanding - diluted	499	438