Commitments and Contingencies - Lead Pigment Litigation-NL and Environmental Matters and Litigation - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014 Cases	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Commitments And Contingent Liabilities [Line Items]
Accrual for reasonably estimable environmental remediation and related matters	118,500,000	$ 122,700,000	$ 50,200,000	$ 43,200,000
Other Environmental Cleanup Matters
Commitments And Contingent Liabilities [Line Items]
Accrual for reasonably estimable environmental remediation and related matters	8,500,000
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	110,000,000
Number of sites associated with remediation ad related costs	47
Upper end range, estimate costs for remediation and related matters	149,000,000
Number of sites for which NL not currently able to estimate range of costs	5
Lead Pigment Litigation | NL
Commitments And Contingent Liabilities [Line Items]
Number of cases settled and dismissed and found not liable	100
Period by which loss contingency claims settled and dismissed	20 years
California Lead Paint Litigation | NL
Commitments And Contingent Liabilities [Line Items]
Payments for litigation	1,150,000,000