Earnings Per Share and Common Stock - Reconciliation of Information Used to Compute Basic and Diluted EPS (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Earnings Per Share [Abstract]
Net income attributable to common shareholders	$ 193	$ 147	$ 341	$ 278
Less: preferred stock dividends declared	0	0	1	1
Net income available to Howmet Aerospace common shareholders - basic	193	147	340	277
Net income available to Howmet Aerospace common shareholders - diluted	$ 193	$ 147	$ 340	$ 277
Average shares outstanding - basic (in shares)	413	417	413	418
Effect of dilutive securities:
Stock and performance awards (in shares)	4	5	4	5
Average shares outstanding - diluted (in shares)	417	422	417	423