Subsequent Events	6 Months Ended
	Jun. 30, 2024
Subsequent Events [Abstract]
Subsequent Event	Subsequent EventOn August 2, 2024, the Company received notice that it and certain of its affiliates are parties to a lawsuit captioned William L. Schoen, Mary J. Nesbit, Robin L. Rosewicz, George E. Poole and James E. Swartz, Jr., individually and as representatives of a class of participants and beneficiaries of the Allegheny Technologies Incorporated Pension Plan v. ATI Inc., The Allegheny Technologies Incorporated Pension Plan Administrative Committee, State Street Global Advisors Trust Co., and John Does 1-5 (Case No. 2:24-cv-01109) and filed in federal district court for the Western District of Pennsylvania. The lawsuit asserts various claims associated with the Company’s October 2023 purchase of group annuity contracts to transfer a portion of its U.S. qualified defined benefit pension plan obligations to Athene Annuity and Life Company and Athene Annuity & Life Assurance of New York. The Company disputes and intends to vigorously defend against these claims, but given the preliminary nature of these matters, cannot predict their outcome or estimate any range of reasonably possible loss at this time.