Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands		3 Months Ended					6 Months Ended		12 Months Ended
	Jun. 30, 2017	Dec. 31, 2019	Sep. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Line Items]
Dividends received from Kronos Worldwide, Inc.									$ 25,356	$ 23,948	$ 21,132
Unrecognized tax benefits, if recognize which would affect effective tax rate		$ 7,300							7,300
Uncertain tax position		4,053							$ 4,053	$ 7,312
U.S. federal corporate income tax rate									21.00%	21.00%	35.00%
Deferred income tax benefit from change in enacted tax rate					$ (37,500)					$ 800	$ (37,500)
Currently payable (receivable)									$ 200	(200)	(100)
Income tax expense (benefit)									(579)	15,361	5,634
Current payable to affiliate		801							801	567
Cash tax refund									200	1,700
Federal Income Tax Purposes
Income Tax Disclosure [Line Items]
Net operating loss carryforwards		$ 15,500							$ 15,500
Annual usage limitation		80.00%							80.00%
Net operating loss carryforwards expiration description									an indefinite carryforward period subject to an 80% annual usage limitation
Kronos
Income Tax Disclosure [Line Items]
Dividends received from Kronos Worldwide, Inc.									$ 25,400	23,900	21,100
Kronos | Germany
Income Tax Disclosure [Line Items]
Net income tax benefit		$ 3,000
Current cash tax benefit		1,500
Non-cash deferred income tax benefit		1,500
Deferred income tax expense resulting from decrease in trade tax rate		5,500
Kronos | Expected Future Periods Net Operating Loss Utilization
Income Tax Disclosure [Line Items]
Increase (decrease) in non-cash deferred income tax asset valuation allowance	$ (149,900)
Kronos | Effect of Currency Exchange Rates
Income Tax Disclosure [Line Items]
Increase (decrease) in non-cash deferred income tax asset valuation allowance											(13,700)
Kronos | German
Income Tax Disclosure [Line Items]
Deferred income tax asset valuation allowance												$ 153,000
Kronos | German | Expected Future Periods Net Operating Loss Utilization
Income Tax Disclosure [Line Items]
Increase (decrease) in non-cash deferred income tax asset valuation allowance	(141,900)
Kronos | Belgium
Income Tax Disclosure [Line Items]
Deferred income tax asset valuation allowance												20,000
Kronos | Belgium | Expected Future Periods Net Operating Loss Utilization
Income Tax Disclosure [Line Items]
Increase (decrease) in non-cash deferred income tax asset valuation allowance	$ (8,000)
Kronos | Non-US
Income Tax Disclosure [Line Items]
Deferred income tax asset valuation allowance												$ 173,000
Increase (decrease) in non-cash deferred income tax asset valuation allowance											$ (186,700)
Kronos | Non-US | Current Periods Net Operating Loss Utilization
Income Tax Disclosure [Line Items]
Increase (decrease) in non-cash deferred income tax asset valuation allowance							$ (24,100)	$ (12,700)
Kronos | European and Candadian Subsidiaries | Undistributed Earnings Previously Considered to be Permanently Reinvested
Income Tax Disclosure [Line Items]
Aggregate provisional non-cash deferred income tax expense (benefit)					4,500					2,400
Kronos | One Non US Subsidiary | Expected Future Periods Net Operating Loss Utilization | Valuation Allowance of Deferred Tax Assets | Non-cash Deferred Income Tax Benefit
Income Tax Disclosure [Line Items]
Increase (decrease) in non-cash deferred income tax asset valuation allowance					(18,700)
Kronos | Deferred Tax Liability Non Current
Income Tax Disclosure [Line Items]
Uncertain tax position		3,300							3,300
Kronos | Corporate Tax Purposes | German
Income Tax Disclosure [Line Items]
Net operating loss carryforwards		501,000							501,000
Kronos | Corporate Tax Purposes | Belgium
Income Tax Disclosure [Line Items]
Net operating loss carryforwards		8,000							8,000
Kronos | GILTI | United States
Income Tax Disclosure [Line Items]
Currently payable (receivable)									$ 2,400	$ 3,700
Kronos European Subsidiaries | Valhi
Income Tax Disclosure [Line Items]
Income tax liability payable period									8 years
Kronos European Subsidiaries | Valhi | Income Tax Payable
Income Tax Disclosure [Line Items]
Payable to affiliate		62,600							$ 62,600
Noncurrent payable to affiliate		56,600							56,600
Current payable to affiliate		$ 6,000							6,000
Kronos European Subsidiaries | Transition Tax
Income Tax Disclosure [Line Items]
Currently payable (receivable)					$ 76,200
Current income tax expense payment period					8 years
Income tax expense (benefit)			$ 1,700
Kronos Canadian Subsidiary | Canada-Germany APA
Income Tax Disclosure [Line Items]
Non-cash income tax benefit						$ 8,100			$ 8,600
Kronos Canadian Subsidiary | Canada Revenue Agency | Canada-Germany APA | Earliest Tax Year
Income Tax Disclosure [Line Items]
Effective tax year						2005
Kronos Canadian Subsidiary | Canada Revenue Agency | Canada-Germany APA | Latest Tax Year
Income Tax Disclosure [Line Items]
Effective tax year						2017
Kronos Canadian Subsidiary | German | Canada-Germany APA
Income Tax Disclosure [Line Items]
Non-cash income tax benefit						$ 2,600
Cash tax refund						$ 600
Kronos German Subsidiary | Germany Revenue Agency | Germany- Canada APA | Earliest Tax Year
Income Tax Disclosure [Line Items]
Effective tax year				2005
Kronos German Subsidiary | Germany Revenue Agency | Germany- Canada APA | Latest Tax Year
Income Tax Disclosure [Line Items]
Effective tax year				2017
Kronos Canadian And German Subsidiaries | Germany- Canada APA
Income Tax Disclosure [Line Items]
Non-cash income tax benefit				$ 1,400