Commitments and Contingencies - Lead Pigment Litigation-NL and Environmental Matters and Litigation - Additional Information (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2015 USD ($) Cases site	Dec. 31, 2014 USD ($)
Commitments And Contingent Liabilities [Line Items]
Accrual for reasonably estimable environmental remediation and related matters	$ 120.7	$ 118.5
Other Environmental Cleanup Matters
Commitments And Contingent Liabilities [Line Items]
Accrual for reasonably estimable environmental remediation and related matters	8.7
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	$ 112.0
Number of sites associated with remediation ad related costs | site	46
Upper end range, estimate costs for remediation and related matters	$ 165.0
Number of sites for which NL not currently able to estimate range of costs | site	5
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