Inventories (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Inventories:
Finished goods	$ 399.7	$ 350.0
Work in process	276.8	275.4
Raw materials, supplies and other	363.7	335.6
First-in, first-out inventory	1,040.2	961.0
Less: Excess of first-in, first-out cost over last-in, first-out cost	(158.3)	(160.8)
Net inventories	$ 881.9	$ 800.2