Statement of Changes in Consolidated Equity - USD ($) $ in Millions	Total	Preferred Class A [Member]	Preferred Class B [Member]	Preferred Stock [Member]	Mandatory Convertible Preferred Stock [Member]	Common Stock [Member]	Additional Capital [Member]	Retained (Deficit) Earnings [Member]	Retained (Deficit) Earnings [Member] Preferred Class A [Member]	Retained (Deficit) Earnings [Member] Preferred Class B [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interests [Member]
Balance at Dec. 31, 2013	$ 13,522			$ 55		$ 1,178	$ 7,509	$ 9,272			$ (3,762)	$ (3,659)	$ 2,929
Net (loss) income	177							268					(91)
Other comprehensive loss (B)	(1,272)											(1,018)	(254)
Cash dividends declared:
Preferred share, value		$ (2)	$ (19)						$ (2)	$ (19)
Common share, value	(140)							(140)
Stock-based compensation (P)	87						87
Common stock issued: compensation plans (P)	136						(584)				720
Issuance of mandatory convertible preferred stock (P)	1,213				$ 3		1,210
Issuance of common stock (F and P)	1,185					126	1,059
Distributions	(120)												(120)
Contributions	53												53
Purchase of equity from noncontrolling interest	(28)						3						(31)
Other	2												2
Balance at Dec. 31, 2014	14,794			55	3	1,304	9,284	9,379			(3,042)	(4,677)	2,488
Net (loss) income	(197)							(322)					125
Other comprehensive loss (B)	(1,176)											(754)	(422)
Cash dividends declared:
Preferred share, value		(2)	(67)						(2)	(67)
Common share, value	(154)							(154)
Equity option on convertible notes (F)	55						55
Stock-based compensation (P)	92						92
Common stock issued: compensation plans (P)	22						(195)				217
Issuance of common stock (F and P)	870					87	783
Distributions	(106)												(106)
Contributions	2												2
Other	(2)												(2)
Balance at Dec. 31, 2015	14,131			55	3	1,391	10,019	8,834			(2,825)	(5,431)	2,085
Net (loss) income	(878)							(941)					63
Other comprehensive loss (B)	(507)											(691)	184
Cash dividends declared:
Preferred share, value		$ (2)	$ (67)						$ (2)	$ (67)
Common share, value	(159)							(159)
Stock-based compensation (P)	86						86
Common stock issued: compensation plans (P)	(19)						(205)				186
Retirement of Treasury stock (P)						(76)	(2,563)				$ 2,639
Reverse stock split (A and P)						(877)	877
Distribution of Alcoa Corporation	(7,271)							(8,692)				3,554	(2,133)
Distributions	(226)												(226)
Contributions	51												51
Other	2												2
Balance at Dec. 31, 2016	$ 5,141			$ 55	$ 3	$ 438	$ 8,214	$ (1,027)				$ (2,568)	$ 26