Business Segments - Schedule of Sales and Profit by Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 29, 2026	Mar. 30, 2025
Segment Reporting Information [Line Items]
Sales	$ 1,151.5	$ 1,144.4
Segment EBITDA	249.9	214.4
Corporate expenses	(17.0)	(17.4)
Closed operations and other income	(1.2)	(2.4)
Depreciation & amortization	(45.0)	(40.8)
Interest expense, net	(23.7)	(23.0)
Restructuring and other charges	(26.4)	(5.6)
Loss on sales of businesses	0.0	(3.7)
Income before taxes	136.6	121.5
Operating Segments
Segment Reporting Information [Line Items]
Sales	1,292.2	1,261.7
Depreciation & amortization	(45.0)	(40.8)
Operating Segments | HPMC
Segment Reporting Information [Line Items]
Sales	655.4	644.0
Allocated corporate overhead	15.6	15.8
Other segment items	486.9	497.2
Segment EBITDA	152.9	131.0
Depreciation & amortization	(19.6)	(19.7)
Operating Segments | AA&S
Segment Reporting Information [Line Items]
Sales	636.8	617.7
Allocated corporate overhead	16.3	16.1
Other segment items	523.5	518.2
Segment EBITDA	97.0	83.4
Depreciation & amortization	(23.7)	(19.5)
Sales to external customers | Operating Segments
Segment Reporting Information [Line Items]
Sales	1,151.5	1,144.4
Sales to external customers | Operating Segments | HPMC
Segment Reporting Information [Line Items]
Sales	614.3	584.1
Sales to external customers | Operating Segments | AA&S
Segment Reporting Information [Line Items]
Sales	537.2	560.3
Intersegment sales | Operating Segments
Segment Reporting Information [Line Items]
Sales	140.7	117.3
Intersegment sales | Operating Segments | HPMC
Segment Reporting Information [Line Items]
Sales	41.1	59.9
Intersegment sales | Operating Segments | AA&S
Segment Reporting Information [Line Items]
Sales	$ 99.6	$ 57.4