Inventories (Details) - USD ($) $ in Millions		Sep. 30, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Raw materials		$ 44.4	$ 42.9
Work in process		314.7	332.9
Finished goods		1,121.4	936.7
Other Inventory, Inventory at off Site Premises, Gross	[1]	98.5	0.0
Operating materials and supplies		87.2	78.6
Total Inventory		$ 1,666.2	$ 1,391.1

[1] Final price deferred is product that has shipped to customers, but the price has not yet been agreed upon. For arrangements entered into prior to January 1, 2017, this was not included in inventory as risk of loss had passed to our customers. Beginning in 2017, the provisions of these arrangements changed so that risk of loss does not pass to the customer until the time control transfers and, accordingly, the amounts are reported in inventory.