Inventories (Details) - USD ($) $ in Millions		Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials		$ 118.4		$ 37.8
Work in process		611.3		349.9
Finished goods		1,073.0		1,035.1
Other Inventory, Inventory at off Site Premises, Gross	[1]	38.1		38.6
Operating materials and supplies		116.3		85.8
Total Inventory		$ 1,957.1	$ 1,533.9	$ 1,547.2

[1] Final price deferred is product that has shipped to customers, but the price has not yet been agreed upon.