Statement of Consolidated Operations (unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Sales	$ 1,209	$ 1,634
Cost of goods sold (exclusive of expenses below)	873	1,183
Selling, general administrative, and other expenses	65	79
Research and development expenses	5	4
Provision for depreciation and amortization	68	71
Restructuring and other charges	9	39
Operating income	189	258
Interest expense, net	72	84
Other expense (income), net	4	(24)
Income before income taxes	113	198
Provision for income taxes	33	45
Income from continuing operations after income taxes	80	153
Income from discontinued operations after income taxes	0	62
Net income	80	215
Amounts Attributable to Howmet Aerospace Common Shareholders
Net income	$ 79	$ 214
Earnings per share - basic
Continuing operations (in usd per share)	$ 0.18	$ 0.35
Discontinued operations (in usd per share)	0	0.14
Earnings per share - diluted
Continuing operations (in usd per share)	0.18	0.35
Discontinued operations (in usd per share)	$ 0	$ 0.14
Average Shares Outstanding
Average shares outstanding - basic (in shares)	434	435
Average shares outstanding - diluted (in shares)	439	440