Investment in TiO2 Manufacturing Joint Venture and Other Assets - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Apr. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other Assets Non Current [Line Items]
Equity ownership percentage		50.00%
Indefinite-lived intangible asset		$ 5.1	$ 5.1
Collateral Trust
Other Assets Non Current [Line Items]
Decrease in restricted cash	$ 18.0
Capitalized Operating Permit Costs
Other Assets Non Current [Line Items]
Amortization of capitalized operating permit costs		6.3	6.6	$ 6.5
Capitalized operating permits, net of amortization		31.6	$ 25.3
Capitalized Operating Permit Costs | Permits Subject to Amortization
Other Assets Non Current [Line Items]
Amortization next fiscal year		6.3
Amortization, year 2		6.3
Amortization, year 3		5.7
Amortization, year 4		5.3
Amortization, year 5		5.3
BMI
Other Assets Non Current [Line Items]
Equity ownership percentage				32.00%
BMI | Customer Relationships
Other Assets Non Current [Line Items]
Indefinite-lived intangible asset		$ 5.1
LandWell
Other Assets Non Current [Line Items]
Equity ownership percentage				12.00%
LandWell | General Partner
Other Assets Non Current [Line Items]
Indirect controlling interest in subsidiary				50.00%
LPC
Other Assets Non Current [Line Items]
Purchase of TiO2 from the plant		52.00%