Per Share Information (Tables)

3 Months Ended

Mar. 31, 2019

Earnings Per Share [Abstract]

Schedule Of Earnings Per Share Diluted By Common Class

The following table sets forth the computation of basic and diluted income per common share:

	Three months ended
(In millions, except per share amounts)	March 31,
	2019		2018
Numerator:
Numerator for basic income per common share –
Net income attributable to ATI	$	15.0	$	58.0
Effect of dilutive securities:
4.75% Convertible Senior Notes due 2022	—		3.2
Numerator for diluted income per common share –
Net income attributable to ATI after assumed conversions	$	15.0	$	61.2
Denominator:
Denominator for basic net income per common share – weighted average shares	125.4		125.0
Effect of dilutive securities:
Share-based compensation	0.7		0.6
4.75% Convertible Senior Notes due 2022	—		19.9
Denominator for diluted net income per common share – adjusted weighted average shares and assumed conversions	126.1		145.5
Basic net income attributable to ATI per common share	$	0.12	$	0.46
Diluted net income attributable to ATI per common share	$	0.12	$	0.42