v3.25.3

Earnings Per Share - Schedule of EPS (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Earnings Per Share [Abstract]
Net income attributable to Century stockholders	$ 14.9	$ 47.3	$ 40.0	$ 291.6
Less: net income allocated to participating securities	0.8	2.5	2.0	15.5
Basic EPS:
Net income allocated to common stockholders	$ 14.1	$ 44.8	$ 38.0	$ 276.1
Net income allocated to common stockholders (in shares)	93.3	92.8	93.3	92.7
Net income allocated to common stockholders (in dollars per share)	$ 0.15	$ 0.48	$ 0.41	$ 2.98
Effect of Dilutive Securities
Share-based compensation	$ 0.0	$ 0.0	$ 0.0	$ 1.2
Share-based compensation (in shares)	1.3	1.0	1.3	1.5
Convertible senior notes	$ 0.7	$ 0.7	$ 0.0	$ 2.7
Convertible senior notes (in shares)	4.6	4.6	0.0	4.6
Diluted EPS:
Net income allocated to common stockholders	$ 14.8	$ 45.5	$ 38.0	$ 280.0
Net income allocated to common stockholders (in shares)	99.2	98.4	94.6	98.8
Net income allocated to common stockholders (in dollars per share)	$ 0.15	$ 0.46	$ 0.40	$ 2.83

Amount of increase (decrease) to net income used for calculating diluted earnings per share (EPS), resulting from the assumed exercise of stock options or restrictive stock units (RSUs).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482662/260-10-50-1

CENTURY ALUMINUM CO 10-Q