Inventories, Net - Inventories, Net (Detail) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Inventory [Line Items]
Raw materials	$ 140.2	$ 95.8
Work in process	38.7	34.6
Finished products	260.6	320.9
Supplies (chemicals)	67.7	64.5
Total	507.2	515.8
Chemicals
Inventory [Line Items]
Raw materials	137.0	93.1
Work in process	27.3	23.5
Finished products	257.4	317.6
Component Products
Inventory [Line Items]
Raw materials	3.2	2.7
Work in process	11.4	11.1
Finished products	$ 3.2	$ 3.3

Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of merchandise or goods held by the company that are readily available for sale.

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