Debt (Tables)

6 Months Ended

Jun. 30, 2018

Debt Disclosure [Abstract]

Schedule of Debt Instruments

Debt at June 30, 2018 and December 31, 2017 was as follows (in millions):

	June 30, 2018			December 31, 2017
Allegheny Technologies 5.875% Notes due 2023 (a)	$	500.0		$	500.0
Allegheny Technologies 5.95% Notes due 2021	500.0			500.0
Allegheny Technologies 4.75% Convertible Senior Notes due 2022	287.5			287.5
Allegheny Ludlum 6.95% debentures due 2025	150.0			150.0
Term Loan due 2022	100.0			100.0
U.S. revolving credit facility	—			—
Foreign credit facilities	9.7			6.3
Other	16.4			10.0
Debt issuance costs	(11.8		)	(13.1		)
Total debt	1,551.8			1,540.7
Short-term debt and current portion of long-term debt	16.3			10.1
Total long-term debt	$	1,535.5		$	1,530.6

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