Consolidated Statements of Income and Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Statement [Abstract]
Net sales	$ 1,979.5	$ 1,976.3
Cost of sales	(1,609.1)	(1,544.9)
Gross profit	370.4	431.4
Selling, general and administrative expenses	(151.9)	(148.2)
Other expense, net	(22.5)	(12.5)
Income from operations	196.0	270.7
Non-operating pension (expense) income	1.1	(2.0)
Interest expense, net	(9.6)	(15.4)
Income before taxes	187.5	253.3
Provision for income taxes	(40.6)	(63.2)
Net income	$ 146.9	$ 190.1
Net income per common share:
Basic	$ 1.64	$ 2.12
Diluted	1.63	2.11
Dividends declared per common share	$ 1.25	$ 1.25
Statements of Comprehensive Income:
Net Income (Loss)	$ 146.9	$ 190.1
Changes in unrealized (losses) gains on marketable debt securities, net of tax of $0.0 million and ($0.2) million for 2024 and 2023, respectively	(0.1)	0.5
Amortization of pension and postretirement plans actuarial loss and prior service cost, net of tax of ($0.4) million and ($0.6) million for 2024 and 2023, respectively	1.0	1.6
Other comprehensive income	0.9	2.1
Comprehensive income	$ 147.8	$ 192.2