Segment and Geographic Area Information - Schedule of Segment Operating Profit to Consolidated Net Income (Loss) Income Attributable to Arconic (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Total segment operating profit	$ 748	$ 626	$ 579
Loss on debt redemption	(146)	(64)	0
Interest expense, net	(259)	(317)	(338)
Other expense, net	(19)	(74)	(31)
Income before income taxes	324	171	210
Total segment sales
Segment Reporting Information [Line Items]
Total segment operating profit	939	890	1,390
Restructuring and other charges
Segment Reporting Information [Line Items]
Total segment operating profit	(90)	(182)	(582)
Corporate expense
Segment Reporting Information [Line Items]
Total segment operating profit	$ (101)	$ (82)	$ (229)