Consolidated Statements of Income and Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Net sales	$ 1,470.8	$ 1,518.9	$ 4,350.8	$ 4,418.7
Cost of sales	(1,142.5)	(1,198.6)	(3,427.9)	(3,486.2)
Gross profit	328.3	320.3	922.9	932.5
Selling, general, and administrative expenses	(112.7)	(119.6)	(345.9)	(359.0)
Other income (expense), net	3.8	(12.3)	(2.9)	(44.0)
Income from operations	219.4	188.4	574.1	529.5
Interest expense, net	(21.7)	(23.1)	(63.2)	(65.3)
Income before taxes	197.7	165.3	510.9	464.2
Income tax provision	(69.9)	(60.9)	(178.3)	(170.1)
Net income	$ 127.8	$ 104.4	$ 332.6	$ 294.1
Net income per common share:
Basic (in dollars per share)	$ 1.31	$ 1.06	$ 3.39	$ 2.99
Diluted (in dollars per share)	1.31	1.06	3.39	2.99
Dividends declared per common share	$ 0.55	$ 0.40	$ 1.65	$ 1.20
Statements of Comprehensive Income:
Net income	$ 127.8	$ 104.4	$ 332.6	$ 294.1
Foreign currency translation adjustment	0.0	(1.6)	2.8	(1.6)
Reclassification adjustments to cash flow hedges included in net income, net of tax of $0.5 million, $0.5 million, $1.6 million, and $1.6 million	0.9	0.9	2.6	2.6
Amortization of pension and postretirement plans actuarial loss and prior service cost, net of tax of $1.4 million, $0.7 million, $4.2 million, and $2.2 million	2.1	1.1	6.5	3.1
Other comprehensive income	3.0	0.4	11.9	4.1
Comprehensive income	$ 130.8	$ 104.8	$ 344.5	$ 298.2