Quarterly Data - Schedule of Quarterly Data (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Sales	$ 2,967	$ 3,138	$ 3,234	$ 3,055	$ 2,991	$ 3,127	$ 3,204	$ 3,091	$ 12,394	$ 12,413	$ 12,542
Net income (loss) attributable to Arconic	$ (1,258)	$ 166	$ 135	$ 16	$ (701)	$ 44	$ 140	$ 195	$ (941)	$ (322)	$ 268
Basic
Continuing operations	$ (2.98)	$ 0.11	$ 0.08	$ 0.21	$ (0.48)	$ 0.05	$ 0.21	$ (0.31)	$ (2.58)	$ (0.54)	$ (0.21)
Discontinued operations	0.07	0.23	0.19	(0.21)	(1.16)	0.01	0.09	0.75	0.27	(0.39)
Net (loss) income per share-basic	(2.91)	0.34	0.27	0.00	(1.64)	0.06	0.30	0.44	(2.31)	(0.93)	0.64
Diluted
Continuing operations	(2.98)	0.11	0.08	0.21	(0.48)	0.05	0.21	(0.31)	(2.58)	(0.54)	(0.21)
Discontinued operations	0.07	0.22	0.19	(0.21)	(1.16)	0.01	0.09	0.74	0.27	(0.39)
Net (loss) income per share-diluted	$ (2.91)	$ 0.33	$ 0.27	$ 0.00	$ (1.64)	$ 0.06	$ 0.30	$ 0.43	$ (2.31)	$ (0.93)	$ 0.63