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 ($)	Sep. 13, 2017	Dec. 31, 2018 USD ($)	Dec. 31, 2018 EUR (€)	Dec. 31, 2017 USD ($)	Dec. 31, 2017 EUR (€)	Dec. 31, 2018 EUR (€)	Sep. 30, 2017 EUR (€)
Foreign Line of Credit | Europe
Line Of Credit Facility [Line Items]
Amount available for borrowing			$ 103,200,000				€ 90,000,000
Revolving credit facility, borrowings (repayments) | €				€ 0		€ 0
Outstanding borrowings under revolving credit facility			0
Revolving North American Credit Facility
Line Of Credit Facility [Line Items]
Line of credit maximum borrowing capacity			$ 125,000,000
Fixed charge coverage ratio, minimum value			100.00%	100.00%
Revolving credit facility, borrowings			$ 0		$ 253,900,000
Repayment of credit facility			0		253,900,000
Debt instrument, average interest rate during period		4.80%
Repayments of line of credit using Senior Notes proceeds	$ 21,000,000
Amount available for borrowing			$ 101,300,000
Revolving North American Credit Facility | Maturity Date Option 1
Line Of Credit Facility [Line Items]
Line of credit, maturity year			2022	2022
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%