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
	Mar. 31, 2024	Mar. 31, 2023
Earnings Per Share [Abstract]
Net income attributable to common shareholders	$ 243	$ 148
Less: preferred stock dividends declared	1	1
Net income available to Howmet Aerospace common shareholders - basic	242	147
Net income available to Howmet Aerospace common shareholders - diluted	$ 242	$ 147
Average shares outstanding - basic (in shares)	410	412
Effect of dilutive securities:
Stock and performance awards (in shares)	2	6
Average shares outstanding - diluted (in shares)	412	418