Debt (Tables)

9 Months Ended

Sep. 30, 2021

Debt Disclosure [Abstract]

Schedule of Debt Instruments

Debt at September 30, 2021 and December 31, 2020 was as follows (in millions): 

	September 30, 2021		December 31, 2020
Allegheny Technologies 5.875% Notes due 2023 (a)	$	500.0	$	500.0
Allegheny Technologies 5.875% Notes due 2027	350.0		350.0
Allegheny Technologies 5.125% Notes due 2031	350.0		—
Allegheny Technologies 4.875% Notes due 2029	325.0		—
Allegheny Technologies 3.5% Convertible Senior Notes due 2025	291.4		291.4
Allegheny Technologies 4.75% Convertible Senior Notes due 2022	84.2		84.2
Allegheny Ludlum 6.95% Debentures due 2025 (b)	150.0		150.0
Term Loan due 2024	200.0		200.0
U.S. revolving credit facility	—		—
Foreign credit facilities	9.2		5.5
Finance leases and other	53.5		48.0
Debt issuance costs	(22.8)		(14.5)
Equity component of convertible debt	—		(46.8)
Total debt	2,290.5		1,567.8
Short-term debt and current portion of long-term debt	606.9		17.8
Total long-term debt	$	1,683.6	$	1,550.0

(a) Bearing interest at 7.875% effective February 15, 2016.

(b) The payment obligations of these debentures issued by Allegheny Ludlum, LLC are fully and unconditionally guaranteed

by ATI.

Interest Income and Interest Expense Disclosure

Interest expense on the 2025 Convertible Notes was as follows:

	Three months ended September 30,				Nine months ended September 30,
(in millions)	2021		2020		2021		2020
Contractual coupon rate	$	2.5	$	2.4	$	7.6	$	2.4
Amortization of debt issuance costs	0.5		0.4		1.3		0.4
Total interest expense	$	3.0	$	2.8	$	8.9	$	2.8

Interest expense on the 2022 Convertible Notes was as follows:

	Three months ended September 30,				Nine months ended September 30,
(in millions)	2021		2020		2021		2020
Contractual coupon rate	$	1.0	$	1.0	$	3.0	$	7.6
Amortization of debt issuance costs	0.2		0.1		0.4		0.9
Total interest expense	$	1.2	$	1.1	$	3.4	$	8.5