Inventories, Net (Tables)

6 Months Ended

Jun. 30, 2018

Inventory Disclosure [Abstract]

Inventories, Net

	December 31, 2017		June 30, 2018
	(In millions)
Raw materials:
Chemicals	$	106.9	$	89.3
Component products		2.7		2.7
Total raw materials		109.6		92.0
Work in process:
Chemicals		20.8		33.1
Component products		9.8		10.6
Total in-process products		30.6		43.7
Finished products:
Chemicals		192.2		226.4
Component products		2.8		3.3
Total finished products		195.0		229.7
Supplies (chemicals)		63.2		64.0
Total	$	398.4	$	429.4