Business Segments (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 30, 2025	Mar. 31, 2024
Segment Reporting Information [Line Items]
Sales	$ 1,144.4	$ 1,042.9
Segment EBITDA	214.4	169.4
Corporate expenses	(17.4)	(17.1)
Closed operations and other income (expenses)	(2.4)	(1.3)
Depreciation & amortization	(40.8)	(36.0)
Interest expense, net	(23.0)	(26.6)
Restructuring and other charges	(5.6)	(3.1)
Loss on sales of business, net	(3.7)	0.0
Income before taxes	121.5	85.3
Operating Segments
Segment Reporting Information [Line Items]
Sales	1,261.7	1,132.6
Depreciation & amortization	(40.8)	(36.0)
Operating Segments \| HPMC
Segment Reporting Information [Line Items]
Sales	644.0	571.9
Allocated corporate overhead	15.8	15.4
Other segment items	497.2	458.9
Segment EBITDA	131.0	97.6
Depreciation & amortization	(19.7)	(16.3)
Operating Segments \| AA&S
Segment Reporting Information [Line Items]
Sales	617.7	560.7
Allocated corporate overhead	16.1	14.9
Other segment items	518.2	474.0
Segment EBITDA	83.4	71.8
Depreciation & amortization	(19.5)	(18.0)
Sales to external customers \| Operating Segments
Segment Reporting Information [Line Items]
Sales	1,144.4	1,042.9
Sales to external customers \| Operating Segments \| HPMC
Segment Reporting Information [Line Items]
Sales	584.1	529.9
Sales to external customers \| Operating Segments \| AA&S
Segment Reporting Information [Line Items]
Sales	560.3	513.0
Intersegment sales \| Operating Segments
Segment Reporting Information [Line Items]
Sales	117.3	89.7
Intersegment sales \| Operating Segments \| HPMC
Segment Reporting Information [Line Items]
Sales	59.9	42.0
Intersegment sales \| Operating Segments \| AA&S
Segment Reporting Information [Line Items]
Sales	$ 57.4	$ 47.7

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