Long-Term Debt - Revolving Credit Facility - Additional Information (Detail) (Kronos Worldwide, Inc.) In Millions, unless otherwise specified	9 Months Ended		3 Months Ended		9 Months Ended		9 Months Ended
	Sep. 30, 2014 Foreign Line of Credit Europe EUR (€)	Sep. 30, 2014 Foreign Line of Credit Europe USD ($)	Jun. 30, 2014 Foreign Line of Credit Canada Bank Of Montreal CAD	Sep. 30, 2014 Foreign Line of Credit Canada Bank Of Montreal CAD	Sep. 30, 2014 Foreign Line of Credit Canada Economic Development Agency Provence of Quebec Canada CAD	Sep. 30, 2014 Foreign Line of Credit Canada Economic Development Agency Provence of Quebec Canada USD ($)	Sep. 30, 2014 Domestic Line of Credit North American Revolving Credit Facility USD ($)
Line Of Credit Facility [Line Items]
Revolving credit facility, borrowings	€ 0						$ 81.0
Repayment of credit facility	0						92.1
Outstanding borrowings under revolving credit facility	0				3.0	2.7
Amount available for borrowing	64.0	81.0					97.0
Percentage of borrowings available under credit facility		53.00%
Percentage of average interest rate, during period							3.75%
Aggregate letter of credit outstanding amount				0.3
Maximum amount of letters of credit available to be issued				10.0
Aggregate letters of credit cancelled			7.6
Borrowings under credit facility during the period					1.2