Commitments and Contingencies - Lead Pigment Litigation-NL and Environmental Matters and Litigation - Additional Information (Detail) $ in Millions		3 Months Ended
	Jul. 24, 2019 USD ($) Installment	Mar. 31, 2021 USD ($) Cases site	Dec. 31, 2020 USD ($)
Commitments And Contingent Liabilities [Line Items]
Accrual for reasonably estimable environmental remediation and related matters		$ 98.2	$ 98.6
Other Environmental Cleanup Matters
Commitments And Contingent Liabilities [Line Items]
Accrual for reasonably estimable environmental remediation and related matters		5.0
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		$ 93.0
Number of sites associated with remediation and related costs | site		32
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		$ 114.0
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		30 years
California Lead Paint Litigation | NL
Commitments And Contingent Liabilities [Line Items]
Number of annual installments | Installment	5
Remaining litigation settlement charge due in first installment	$ 12.0
Remaining litigation settlement charge due in second installment	12.0
Remaining litigation settlement charge due in third installment	12.0
Remaining litigation settlement charge due in fourth installment	12.0
Remaining litigation settlement charge due in fifth installment	$ 16.7