Restructuring Costs (Details) $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($) employee	Dec. 31, 2021 USD ($) employee	Dec. 31, 2020 USD ($) position
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges (credits)	$ 23.7	$ (10.5)	$ 1,132.1
Non-cash restructuring charges	0.0	0.0	1,041.5
Restructuring charges (credits)	(4.8)	(11.3)	1,107.5
Severance costs			$ 60.5
Restructuring and Related Cost, Expected Number of Positions Eliminated | position			1,400
Inventory write-down		0.8	$ 7.2
Termination benefits			17.4
Restructuring Reserve [Roll Forward]
Other nonoperating income (expense), litigation reserve	$ (28.5)	0.0	0.0
Brackenridge PA Operations
Restructuring Cost and Reserve [Line Items]
Asset impairment charges			1,032.6
Fair value			$ 354.0
Brackenridge PA Operations | Weighted average cost of capital | Fair Value, Inputs, Level 3 [Member]
Restructuring Cost and Reserve [Line Items]
Long-Lived Asset, Measurement Input			0.093
Brackenridge PA Operations | Long-term growth rate | Fair Value, Inputs, Level 3 [Member]
Restructuring Cost and Reserve [Line Items]
Long-Lived Asset, Measurement Input			0.02
Various AA&S Segment Operations
Restructuring Cost and Reserve [Line Items]
Asset impairment charges			$ 8.9
Facility Idling
Restructuring Cost and Reserve [Line Items]
Restructuring charges (credits)			5.5
Restructuring Reserve [Roll Forward]
Restructuring Charges		$ 0.7
Employee Severance
Restructuring Cost and Reserve [Line Items]
Reduction in severance related reserves, workforce | employee	110	350
Restructuring Reserve [Roll Forward]
Restructuring Reserve, Beginning Balance	$ 17.7	$ 43.4	4.5
Restructuring Charges	(4.8)	(12.0)	60.5
Payments for Restructuring	(3.1)	(13.7)	(21.6)
Restructuring Reserve, Ending Balance	9.8	17.7	$ 43.4
Other Current Liabilities [Member]
Restructuring Reserve [Roll Forward]
Restructuring Reserve, Beginning Balance	11.4
Restructuring Reserve, Ending Balance	5.4	11.4
Other Noncurrent Liabilities [Member]
Restructuring Reserve [Roll Forward]
Restructuring Reserve, Beginning Balance	6.3
Restructuring Reserve, Ending Balance	$ 4.4	$ 6.3