Inventory (Tables)

12 Months Ended

Dec. 31, 2017

Inventory Disclosure [Abstract]

Components of inventory

The components of inventory are summarized as follows:

	As of December 31,
(In millions)	2017		2016
Raw materials	$	162.4	$	170.4
Work in process	605.7		698.7
Finished goods	157.4		170.3
Total inventory	$	925.5	$	1,039.4
Balance Sheet Classification:
Inventory	$	902.7	$	1,001.6
Investments and other assets	22.8		37.8
Total inventory	$	925.5	$	1,039.4