Supplementary Financial Statement Information - Inventory (Details3) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Inventory Disclosure [Abstract]
Finished and semi-finished	$ 1,009.6	$ 855.0
Raw materials	408.5	415.8
Total cost	1,418.1	1,270.8
Adjustment to state inventories at LIFO value	(270.3)	(156.9)	$ (180.2)	$ (375.5)
Inventory, net	1,147.8	1,113.9
Effect of LIFO inventory liquidation on income	$ (2.9)	$ (6.0)	$ 0.0