Inventories, Net (Tables)

9 Months Ended

Sep. 30, 2018

Inventory Disclosure [Abstract]

Inventories, Net

	December 31, 2017		September 30, 2018
	(In millions)
Raw materials:
Chemicals	$	106.9	$	106.1
Component products		2.7		3.0
Total raw materials		109.6		109.1
Work in process:
Chemicals		20.8		26.6
Component products		9.8		10.9
Total in-process products		30.6		37.5
Finished products:
Chemicals		192.2		249.6
Component products		2.8		3.3
Total finished products		195.0		252.9
Supplies (chemicals)		63.2		64.7
Total	$	398.4	$	464.2