Commitments and Contingencies - Other Litigation and Other Matters - Additional Information (Detail)	1 Months Ended		3 Months Ended	12 Months Ended
	Apr. 30, 2021	Apr. 30, 2014 USD ($)	Sep. 30, 2014 USD ($)	Dec. 31, 2016 USD ($) Cases Plaintiff Customer	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2011
Commitments And Contingent Liabilities [Line Items]
Rent expense				$ 16,100,000	$ 16,100,000	$ 16,600,000
Chemicals | Minimum | Various Supply and Services Agreements
Commitments And Contingent Liabilities [Line Items]
Long term master agreements expiring				2017
Chemicals | Maximum | Various Supply and Services Agreements
Commitments And Contingent Liabilities [Line Items]
Long term master agreements expiring				2019
Chemicals | TiO2 Product
Commitments And Contingent Liabilities [Line Items]
Sale of TiO2, number of customers | Customer				4,000
Chemicals | Customer Concentration Risk | Behr Process Corporation | Net Sales
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage				10.00%	10.00%	10.00%
Component Products Segment | Customer Concentration Risk | Top Ten Customers | Net Sales
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage				46.00%	48.00%	47.00%
Component Products | Customer Concentration Risk | United States Postal Service | Net Sales | Security​ Products​ Reporting​ Unit​
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage				14.00%	13.00%	13.00%
Component Products | Customer Concentration Risk | Harley Davidson Inc | Net Sales | Security​ Products​ Reporting​ Unit​
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage				11.00%	12.00%	12.00%
Waste Management | Customer Concentration Risk | Net Sales | Minimum
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage				10.00%	10.00%	10.00%
Waste Management | Customer Concentration Risk | Zion Solutions | Net Sales
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage					11.00%	18.00%
Waste Management | Customer Concentration Risk | Sacramento Municipal Utility District | Net Sales
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage						23.00%
Waste Management | Customer Concentration Risk | Exelon Generation | Net Sales
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage				12.00%	19.00%
Waste Management | Customer Concentration Risk | U.S. Department of Energy | Net Sales
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage				27.00%	16.00%
Waste Management | Customer Concentration Risk | Nuclear Waste Partnership | Net Sales
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage					12.00%
Waste Management | Customer Concentration Risk | Arizona Public Service | Net Sales
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage					12.00%
Waste Management | Customer Concentration Risk | Pacific Gas & Electric Company | Net Sales
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage				13.00%
Real Estate Management And Development | Customer Concentration Risk | Net Sales | Minimum
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage				10.00%	10.00%	10.00%
Real Estate Management And Development | Customer Concentration Risk | Greystone Nevada | Net Sales
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage				34.00%		23.00%
Real Estate Management And Development | Customer Concentration Risk | Woodside Homes of Nevada | Net Sales
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage						25.00%
Real Estate Management And Development | Customer Concentration Risk | Richmond Homes of Nevada | Net Sales
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage				15.00%	27.00%	20.00%
Real Estate Management And Development | Customer Concentration Risk | City of Henderson | Net Sales
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage					15.00%	12.00%
Real Estate Management And Development | Customer Concentration Risk | LV East Gibson, LLC | Net Sales
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage					17.00%
Real Estate Management And Development | Customer Concentration Risk | Prologis, L.P | Net Sales
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage					11.00%
Real Estate Management And Development | Customer Concentration Risk | Henderson Interchange Centers LLC | Net Sales
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage				12.00%
TiO2 | Chemicals | TiO2 Product | Net Sales
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage				93.00%	92.00%	90.00%
TiO2 | Chemicals | Customer Concentration Risk | Top Ten Customers | Net Sales
Commitments And Contingent Liabilities [Line Items]
Concentration risk percentage				33.00%	34.00%	35.00%
Feedstock Ore | Chemicals
Commitments And Contingent Liabilities [Line Items]
Minimum purchase commitments				$ 605,000,000
Other Supply And Service Contracts | Chemicals
Commitments And Contingent Liabilities [Line Items]
Minimum purchase commitments				158,000,000
Valhi | Surety Bond | Contran | Waste Control Specialists
Commitments And Contingent Liabilities [Line Items]
Surety bond purchased from third party insurance company		$ 85,300,000						$ 32,200,000
Collateral trust as a percent of value of bonds									2.50%
Cash payments to collateral trust		2,000,000		$ 21,600,000
Valhi | Surety Bond | Contran | Scenario, Forecast | Waste Control Specialists
Commitments And Contingent Liabilities [Line Items]
Collateral trust as a percent of value of bonds	50.00%
Valhi | Surety Bond | Contran | Quarterly Payment | Waste Control Specialists
Commitments And Contingent Liabilities [Line Items]
Cash payments to collateral trust			$ 1,300,000
Valhi | Second Collateral Trust | Contran | Waste Control Specialists
Commitments And Contingent Liabilities [Line Items]
Restricted cash							$ 18,000,000
Decrease in restricted cash		$ 18,000,000
City of Henderson Redevelopment Agency | OPA​
Commitments And Contingent Liabilities [Line Items]
Tax increment reimbursement percentage				75.00%
City of Henderson Redevelopment Agency | Maximum | OPA​
Commitments And Contingent Liabilities [Line Items]
Reimbursement revenue				$ 209,000,000
Product Liability And Occupational Exposure Litigation Claims | NL
Commitments And Contingent Liabilities [Line Items]
Cases pending | Cases				103
Product Liability And Occupational Exposure Litigation Claims | NL | Pending Claims
Commitments And Contingent Liabilities [Line Items]
Number of plaintiffs involved | Plaintiff				588
Product Liability And Occupational Exposure Litigation Claims | NL | Administratively Dismissed Claims
Commitments And Contingent Liabilities [Line Items]
Number of plaintiffs involved | Plaintiff				8,687