Consolidated Statements of Income and Comprehensive Income - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Net sales	$ 6,658,200,000	$ 6,964,300,000	$ 7,014,600,000
Cost of sales	(5,288,800,000)	(5,320,300,000)	(5,369,300,000)
Gross profit	1,369,400,000	1,644,000,000.0	1,645,300,000
Selling and administrative expenses	(539,600,000)	(557,600,000)	(536,400,000)
Goodwill impairment	(55,200,000)
Other expense, net	(50,700,000)	(32,700,000)	(41,200,000)
Income from operations	723,900,000	1,053,700,000	1,067,700,000
Non-operating pension income (expense)	2,300,000	(7,900,000)	(2,100,000)
Interest expense, net	(93,500,000)	(128,800,000)	(95,100,000)
Income before taxes	632,700,000	917,000,000.0	970,500,000
Provision for income taxes	(171,700,000)	(220,600,000)	(232,500,000)
Net income	$ 461,000,000.0	$ 696,400,000	$ 738,000,000.0
Net income per common share:
Basic	$ 4.86	$ 7.36	$ 7.82
Diluted	4.84	7.34	7.80
Dividends declared per common share	$ 3.37	$ 3.16	$ 3.00
Statements of Comprehensive Income:
Net income	$ 461,000,000.0	$ 696,400,000	$ 738,000,000.0
Foreign currency translation adjustment			(100,000)
Reclassification adjustments to cash flow hedges included in net income, net of tax of $0.0 million, $7.9 million, and $1.3 million for 2020, 2019, and 2018, respectively		10,200,000	4,000,000.0
Changes in unrealized gains on marketable debt securities, net of tax of $0.1 million, $0.0 million, and $0.0 million for 2020, 2019, and 2018, respectively	300,000
Amortization of pension and postretirement plans actuarial loss and prior service cost, net of tax of $3.6 million, $3.2 million, and $4.0 million for 2020, 2019, and 2018, respectively	10,700,000	9,600,000	11,800,000
Changes in unfunded employee benefit obligations, net of tax of ($1.3) million, $13.6 million, and ($0.8) million for 2020, 2019, and 2018, respectively	4,000,000.0	(40,500,000)	2,400,000
Other comprehensive income (loss)	15,000,000.0	(20,700,000)	18,100,000
Comprehensive income	$ 476,000,000.0	$ 675,700,000	$ 756,100,000