Long-Term Debt - Revolving Credit Facility - Additional Information (Detail) - Kronos Worldwide, Inc.	1 Months Ended		8 Months Ended	12 Months Ended
	Sep. 30, 2017 USD ($)	Jan. 31, 2017	Sep. 13, 2017	Dec. 31, 2017 USD ($)	Dec. 31, 2017 EUR (€)	Dec. 31, 2016 USD ($)	Dec. 31, 2017 EUR (€)	Sep. 30, 2017 EUR (€)	Jun. 30, 2012 USD ($)
Foreign Line of Credit | Europe
Line Of Credit Facility [Line Items]
Outstanding borrowings under revolving credit facility				$ 0
Amount available for borrowing				$ 107,700,000			€ 90,000,000
Revolving credit facility, borrowings (repayments) | €					€ 0
Revolving North American Credit Facility
Line Of Credit Facility [Line Items]
Line of credit maximum borrowing capacity									$ 125,000,000
Line of credit maturity, description				As amended in January 2017, the facility matures the earlier of (i) January 30, 2022 or (ii) 90 days prior to the maturity date of our term loan (or the maturity date of any new term loan constituting a permitted refinancing of the existing term loan). The issuance of the Senior Notes is a permitted refinancing of our term loan, and accordingly, the maturity date of the North American revolving credit facility is January 30, 2022.	As amended in January 2017, the facility matures the earlier of (i) January 30, 2022 or (ii) 90 days prior to the maturity date of our term loan (or the maturity date of any new term loan constituting a permitted refinancing of the existing term loan). The issuance of the Senior Notes is a permitted refinancing of our term loan, and accordingly, the maturity date of the North American revolving credit facility is January 30, 2022.
Fixed charge coverage ratio, minimum value				100.00%	100.00%
Revolving credit facility, borrowings				$ 253,900,000		$ 266,200,000
Repayment of credit facility				253,900,000		$ 266,200,000
Debt instrument, average interest rate during period			4.80%
Repayments of line of credit using Senior Notes proceeds	$ 21,000,000
Outstanding borrowings under revolving credit facility				0
Amount available for borrowing				$ 98,200,000
Revolving North American Credit Facility | Maturity Date Option 1
Line Of Credit Facility [Line Items]
Line of credit, maturity date				Jan. 30, 2022	Jan. 30, 2022
Revolving North American Credit Facility | Maturity Date Option 2
Line Of Credit Facility [Line Items]
Maturity date of term loan		90 days
Line of credit maturity				2022-01	2022-01
Revolving North American Credit Facility | Minimum | Variable Rate
Line Of Credit Facility [Line Items]
Interest rate on outstanding borrowings				1.50%	1.50%
Revolving North American Credit Facility | Minimum | Base Rate Option
Line Of Credit Facility [Line Items]
Interest rate on outstanding borrowings				0.50%	0.50%
Revolving North American Credit Facility | Maximum | Variable Rate
Line Of Credit Facility [Line Items]
Interest rate on outstanding borrowings				2.00%	2.00%
Revolving North American Credit Facility | Maximum | Base Rate Option
Line Of Credit Facility [Line Items]
Interest rate on outstanding borrowings				1.00%	1.00%
Letter Of Credit | Revolving North American Credit Facility
Line Of Credit Facility [Line Items]
Line of credit maximum borrowing capacity				$ 15,000,000
Canadian Subsidiary Revolving Borrowings Maximum | Revolving North American Credit Facility
Line Of Credit Facility [Line Items]
Line of credit maximum borrowing capacity				$ 25,000,000
European Revolving Credit Facility
Line Of Credit Facility [Line Items]
Line of credit maximum borrowing capacity | €								€ 90,000,000
Line of credit facility amended month and year				2017-09	2017-09
Line of credit maturity	Sep. 30, 2022
European Revolving Credit Facility | EURIBOR
Line Of Credit Facility [Line Items]
Interest rate on outstanding borrowings	1.60%