Investment in TiO2 Manufacturing Joint Venture and Other Assets - Components of Net Capitalized Permit Costs (Detail) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Other Noncurrent Assets [Line Items]
Net capitalized permit costs	$ 42.9	$ 48.1
Permits Subject to Amortization
Other Noncurrent Assets [Line Items]
Net capitalized permit costs	40.7	47.3
Permits Not Subject to Amortization
Other Noncurrent Assets [Line Items]
Net capitalized permit costs	2.2	0.8
LLRW license (expires in 2024) | Permits Subject to Amortization
Other Noncurrent Assets [Line Items]
Net capitalized permit costs	39.1	44.7
Byproduct license (expires in 2018) | Permits Subject to Amortization
Other Noncurrent Assets [Line Items]
Net capitalized permit costs	1.5	2.5
Other - (expires 2016 - 2024) | Permits Subject to Amortization
Other Noncurrent Assets [Line Items]
Net capitalized permit costs	$ 0.1	$ 0.1