Income Taxes - Additional Information (Detail) - USD ($) $ in Millions		3 Months Ended			12 Months Ended
	Mar. 27, 2020	Mar. 31, 2020	Dec. 31, 2019	Dec. 31, 2017	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes Disclosure [Line Items]
Income tax examination, description					Tax authorities are examining certain of our U.S. and non-U.S. tax returns and have or may propose tax deficiencies, including penalties and interest. Because of the inherent uncertainties involved in settlement initiatives and court and tax proceedings, we cannot guarantee that these tax matters, if any, will be resolved in our favor, and therefore our potential exposure, if any, is also uncertain.
Income tax expense (benefit)					$ 60.1	$ 15.9	$ 26.5
Business interest income, adjusted taxable income	30.00%
Current income taxes expense (benefit)					51.2	28.2	26.3
Deferred income taxes expense (benefit)					8.9	(12.3)	0.2
Deferred income tax benefit from change in enacted tax rate						(0.2)	4.7
Deferred income taxes					46.2	29.6
CARES act of 2020, Business interest income, adjusted taxable income	50.00%
Cash tax benefit recognized		$ 1.0
Unrecognized tax benefits impact on effective tax rate					6.6
Increase (decrease) in unrecognized tax benefits					3.5
Accrued interest and penalties during the period					0.7	0.8	1.3
Accrued interest and penalties end of the period					0.9	1.3
Contran
Income Taxes Disclosure [Line Items]
Income taxes payable current					1.5	8.3
Income taxes payable noncurrent					$ 44.5	50.4
Germany
Income Taxes Disclosure [Line Items]
Income tax expense (benefit)			$ 3.0
Current income taxes expense (benefit)			1.5
Deferred income taxes expense (benefit)			1.5
Deferred income tax benefit from change in enacted tax rate			$ 4.7
European Subsidiaries | Chemicals | Transition Tax
Income Taxes Disclosure [Line Items]
Current income tax expense provisional pursuant to transition tax				$ 74.1
Income tax liability payable period					8 years			8 years
Payable to affiliate					$ 50.4
European Subsidiaries | Chemicals | Transition Tax | Contran
Income Taxes Disclosure [Line Items]
Income taxes payable current					5.9
Income taxes payable noncurrent					44.5
European Subsidiaries | Chemicals | Income Tax Payable | Transition Tax | Contran
Income Taxes Disclosure [Line Items]
Current income tax expense payable in increments over remainder of eight year period					50.4
Corporate Tax Purposes | Kronos Worldwide, Inc. | Germany | Chemicals
Income Taxes Disclosure [Line Items]
Net operating loss carryforwards					451.0
Corporate Tax Purposes | Kronos Worldwide, Inc. | Belgium | Chemicals
Income Taxes Disclosure [Line Items]
Net operating loss carryforwards					19.0
Direct Investment in Subsidiary | Kronos Worldwide, Inc.
Income Taxes Disclosure [Line Items]
Deferred income taxes expense (benefit)					5.0	$ (2.4)	$ 0.1
Deferred income taxes					45.4
Direct Investment in Subsidiary | Kronos Worldwide, Inc. | Maximum
Income Taxes Disclosure [Line Items]
Deferred income taxes					$ 155.4