Earnings Per Share (Tables)

9 Months Ended

Sep. 30, 2021

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

The share information used to compute basic and diluted EPS attributable to Arconic Corporation common stockholders was as follows (shares in millions):

	Third quarter ended September 30,		Nine months ended September 30,
	2021	2020	2021	2020
Weighted-average shares outstanding – basic	108.7	109.1	109.5	109.0
Dilutive share equivalents:
Stock units	3.3	3.7	—	—
Stock options	0.1	—	—	—
Weighted-average shares outstanding – diluted	112.1	112.8	109.5	109.0
Anti-dilutive share equivalents:
Stock units	—	—	3.3	2.1
Stock options*:
In-the-money	—	—	0.1	—
Out-of-the-money	—	—	—	—
	—	—	3.4	2.1