Commitments and Contingencies - Lead Pigment Litigation-NL and Environmental Matters and Litigation - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($) Cases site	Dec. 31, 2017 USD ($)
Commitments And Contingent Liabilities [Line Items]
Accrual for reasonably estimable environmental remediation and related matters	$ 121.3	$ 117.5
Other Environmental Cleanup Matters
Commitments And Contingent Liabilities [Line Items]
Accrual for reasonably estimable environmental remediation and related matters	5.3
NL | Environmental Remediation Sites NL Named As PRP Or Defendant
Commitments And Contingent Liabilities [Line Items]
Accrual for reasonably estimable environmental remediation and related matters	$ 116.0
Number of sites associated with remediation and related costs | site	38
Number of sites for which NL not currently able to reasonably estimate range of costs | site	5
NL | Maximum | Environmental Remediation Sites NL Named As PRP Or Defendant
Commitments And Contingent Liabilities [Line Items]
Upper end range, estimate costs for remediation and related matters	$ 147.0
Lead Pigment Litigation | NL
Commitments And Contingent Liabilities [Line Items]
Number of cases settled and dismissed and found not liable | Cases	100
Period by which loss contingency claims settled and dismissed	20 years
California Lead Paint Litigation | NL
Commitments And Contingent Liabilities [Line Items]
Amount awarded to the plaintiff	$ 1,150.0