New Accounting Pronouncements - Effects of Adopting ASC 606 (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Condensed Consolidated Statement of Income
Revenue	$ 1,236.1		$ 2,220.8
Cost of goods sold	903.9		1,639.2
Operating income	159.7	$ 146.3	254.4	$ 235.8
Provision for income taxes	31.5	45.0	51.9	71.4
Income from continuing operations	114.7	94.7	172.6	152.6
Net income	113.7	$ 102.3	423.3	$ 164.1
Condensed Consolidated Balance Sheet
Receivables	841.6		841.6		$ 625.7
Inventories	491.2		491.2		448.8
Other current assets	54.3		54.3		73.6
Accrued expenses	253.5		253.5		257.8
Other long-term liabilities	275.5		275.5		288.7
Retained earnings	3,211.5		3,211.5		$ 2,820.8
Accounting Standards Update 2014-09
Condensed Consolidated Balance Sheet
Receivables	841.6		841.6
Inventories	491.2		491.2
Other current assets	54.3		54.3
Accrued expenses	253.5		253.5
Other long-term liabilities	275.5		275.5
Retained earnings	3,211.5		3,211.5
Balances Without Adoption of ASC 606
Condensed Consolidated Statement of Income
Revenue	1,227.1		2,200.8
Cost of goods sold	896.9		1,625.3
Operating income	157.7		248.3
Provision for income taxes	31.0		50.4
Income from continuing operations	113.2		168.0
Net income	112.2		418.7
Condensed Consolidated Balance Sheet
Receivables	799.6		799.6
Inventories	519.5		519.5
Other current assets	53.4		53.4
Accrued expenses	252.0		252.0
Other long-term liabilities	273.5		273.5
Retained earnings	3,205.0		3,205.0
Effect of Change Higher/(Lower) | Accounting Standards Update 2014-09
Condensed Consolidated Statement of Income
Revenue	9.0		20.0
Cost of goods sold	7.0		13.9
Operating income	2.0		6.1
Provision for income taxes	0.5		1.5
Income from continuing operations	1.5		4.6
Net income	1.5		4.6
Condensed Consolidated Balance Sheet
Receivables	42.0		42.0
Inventories	(28.3)		(28.3)
Other current assets	0.9		0.9
Accrued expenses	1.5		1.5
Other long-term liabilities	2.0		2.0
Retained earnings	$ 6.5		$ 6.5