Consolidated Statements of Income and Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Net sales	$ 2,000.1	$ 1,693.7	$ 5,687.1	$ 4,944.0
Cost of sales	(1,489.4)	(1,348.3)	(4,324.0)	(3,907.9)
Gross profit	510.7	345.4	1,363.1	1,036.1
Selling, general and administrative expenses	(144.5)	(127.1)	(435.7)	(409.3)
Goodwill impairment	0.0	0.0	0.0	(55.2)
Other expense, net	(13.4)	(8.8)	(41.7)	(36.9)
Income from operations	352.8	209.5	885.7	534.7
Non-operating pension income	5.0	0.6	14.8	1.7
Interest expense, net	(23.9)	(24.4)	(72.2)	(69.1)
Income before taxes	333.9	185.7	828.3	467.3
Provision for income taxes	(83.2)	(46.6)	(203.7)	(129.9)
Net income	$ 250.7	$ 139.1	$ 624.6	$ 337.4
Net income per common share:
Basic	$ 2.64	$ 1.47	$ 6.58	$ 3.56
Diluted	2.63	1.46	6.55	3.54
Dividends declared per common share	$ 1.00	$ 0.79	$ 3.00	$ 2.37
Statements of Comprehensive Income:
Net income	$ 250.7	$ 139.1	$ 624.6	$ 337.4
Foreign currency translation adjustment	0.4	0.0	0.4	0.0
Changes in unrealized gains (losses) on marketable debt securities, net of tax of $0.0 million, $0.1 million, $0.1 million, and $0.2 million	0.0	(0.2)	(0.2)	0.5
Amortization of pension and postretirement plans actuarial loss and prior service cost, net of tax of $0.8 million, $0.9 million, $2.5 million, and $2.7 million	2.5	2.7	7.5	8.1
Other comprehensive income	2.9	2.5	7.7	8.6
Comprehensive income	$ 253.6	$ 141.6	$ 632.3	$ 346.0