Consolidated Statements of Income and Comprehensive Income - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2025	Mar. 31, 2024
Income Statement [Abstract]
Net sales		$ 2,141.0	$ 1,979.5
Cost of sales		(1,686.3)	(1,609.1)
Gross profit		454.7	370.4
Selling, general and administrative expenses		(161.4)	(151.9)
Other expense, net		(13.0)	(22.5)
Income from operations	[1]	280.3	196.0
Non-operating pension expense		0.0	1.1
Interest expense, net		(12.9)	(9.6)
Income before taxes		267.4	187.5
Provision for income taxes		(63.6)	(40.6)
Net income		$ 203.8	$ 146.9
Net income per common share:
Basic		$ 2.27	$ 1.64
Diluted		2.26	1.63
Dividends declared per common share		$ 1.25	$ 1.25
Statements of Comprehensive Income:
Net Income (Loss)		$ 203.8	$ 146.9
Changes in unrealized gains (losses) on marketable debt securities, net of tax $0.0 million for both 2025 and 2024		0.1	(0.1)
Amortization of pension and postretirement plans actuarial loss and prior service cost, net of tax of ($0.3) million and ($0.4) million for 2025 and 2024, respectively		1.0	1.0
Other comprehensive income		1.1	0.9
Comprehensive income		$ 204.9	$ 147.8

[1] The significant expense categories align with the segment-level information that is regularly provided to the CODM.