Arconic Inc. Separation Transaction and Discontinued Operations - Summary of Results of Discontinued Operations (Details) - Discontinued Operations, Disposed of by Means Other than Sale $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($)
Restructuring Cost and Reserve [Line Items]
Sales	$ 1,575
Cost of goods sold	1,293
Selling, general administrative, research and development and other expenses	101
Provision for depreciation and amortization	58
Restructuring and other charges	(18)
Operating income from discontinued operations	141
Interest expense	7
Other expense, net	41
Income from discontinued operations	93
Provision for income taxes	31
Income from discontinued operations after income taxes	$ 62