Per Share Information (Tables)

6 Months Ended

Jun. 30, 2022

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 (loss) per common share: 

(In millions, except per share amounts)	Three months ended June 30,				Six months ended June 30,
	2022		2021		2022		2021
Numerator:
Numerator for basic loss per common share –
Net loss attributable to ATI	$	(38.0)	$	(49.2)	$	(7.1)	$	(57.1)
Effect of dilutive securities:
4.75% Convertible Senior Notes due 2022	—		—		—		—
3.5% Convertible Senior Notes due 2025	—		—		—		—
Numerator for diluted net loss per common share –
Net loss attributable to ATI after assumed conversions	$	(38.0)	$	(49.2)	$	(7.1)	$	(57.1)
Denominator:
Denominator for basic net loss per common share – weighted average shares	124.6		127.1		125.5		127.0
Effect of dilutive securities:
Share-based compensation	—		—		—		—
4.75% Convertible Senior Notes due 2022	—		—		—		—
3.5% Convertible Senior Notes due 2025	—		—		—		—
Denominator for diluted net loss per common share – adjusted weighted average shares and assumed conversions	124.6		127.1		125.5		127.0
Basic net loss attributable to ATI per common share	$	(0.31)	$	(0.39)	$	(0.06)	$	(0.45)
Diluted net loss attributable to ATI per common share	$	(0.31)	$	(0.39)	$	(0.06)	$	(0.45)