Inventories (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Inventory [Line Items]
Raw materials and supplies	$ 174.8		$ 164.9
Work-in-process	908.9		899.6
Finished goods	171.7		161.3
Total inventories at current cost	1,255.4		1,225.8
Adjustment from current cost to LIFO cost basis	45.6		33.6
Inventory valuation reserves	(119.9)		(104.1)
Total inventories, net	1,181.1		1,155.3
LIFO benefit	12.0	$ 1.8
NRV charge	(12.0)	(1.9)
Net cost of sales impact	0.0	$ (0.1)
Net Realizable Value Reserve [Member]
Inventory [Line Items]
Inventory valuation reserves	$ (45.6)		$ (33.6)