Inventory (Tables)

3 Months Ended

Mar. 31, 2018

Inventory Disclosure [Abstract]

Components of inventory

The components of inventory are summarized as follows:

(In millions)	As of March 31, 2018		As of December 31, 2017
Raw materials	$	164.3	$	162.4
Work in process	594.3		605.7
Finished goods	148.0		157.4
Total inventory	$	906.6	$	925.5
Balance Sheet Classification:
Inventory	$	890.8	$	902.7
Investments and other assets	15.8		22.8
Total inventory	$	906.6	$	925.5