Arconic Inc. Separation Transaction and Discontinued Operations - Summary of Results of Discontinued Operations (Details) - Discontinued Operations, Disposed of by Means Other than Sale - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Restructuring Cost and Reserve [Line Items]
Sales	$ 0	$ 1,575
Cost of goods sold	0	1,293
Selling, general administrative, research and development and other expenses	5	106
Provision for depreciation and amortization	0	58
Restructuring and other charges	0	(18)
Operating (loss) income from discontinued operations	(5)	136
Interest expense	0	7
Other expense, net	0	41
(Loss) income from discontinued operations	(5)	88
Provision for income taxes	7	38
(Loss) income from discontinued operations after income taxes	$ (12)	$ 50