Long-Term Debt - Kronos Term Loan - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended		1 Months Ended		9 Months Ended	1 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Feb. 28, 2014 Kronos Worldwide, Inc. Notes Payable, Other Payables Contran	Feb. 28, 2014 Kronos Worldwide, Inc. Notes Payable, Other Payables 2014 Term Loan	Sep. 30, 2014 Kronos Worldwide, Inc. Notes Payable, Other Payables 2014 Term Loan	Feb. 28, 2014 Kronos Worldwide, Inc. Notes Payable, Other Payables 2014 Term Loan Libor Rate	Feb. 28, 2014 Kronos Worldwide, Inc. Notes Payable, Other Payables 2014 Term Loan Base Rate	Feb. 28, 2014 Kronos Worldwide, Inc. Notes Payable, Other Payables 2014 Term Loan U.S. wholly-owned subsidiaries	Feb. 28, 2014 Kronos Worldwide, Inc. Notes Payable, Other Payables 2014 Term Loan Canadian first-tier European subsidiaries	Jul. 31, 2013 Kronos Worldwide, Inc. Notes Payable, Other Payables 2012 Term Loan	Feb. 28, 2013 Kronos Worldwide, Inc. Notes Payable, Other Payables 2012 Term Loan	Dec. 31, 2013 Kronos Worldwide, Inc. Notes Payable, Other Payables 2012 Term Loan	Dec. 31, 2012 Kronos Worldwide, Inc. Notes Payable, Other Payables 2012 Term Loan
Debt Instrument [Line Items]
Principal amount of promissory note						$ 350,000,000								$ 400,000,000	$ 400,000,000
Percentage of loan issued to principal amount						99.50%
Proceeds from borrowings						348,250,000
Repayment of credit facility					170,000,000							100,000,000	290,000,000
Minimum LIBOR rate								1.00%
Debt instrument, Variable rate spread								3.75%	2.75%
Quarterly principal repayments						875,000
Quarterly principal repayments, commencing date						Jun. 30, 2014
Loans maturity period						Feb. 28, 2020
Long term debt prepayments terms						Voluntary principal prepayments are permitted at any time, provided that a call premium of 1% of the principal amount of such prepayment applies to any voluntary prepayment made on or before February 2015 (there is no prepayment penalty applicable to any voluntary prepayment after February 2015)
Call premium percentage						1.00%
Voluntary prepayment, earliest date						Feb. 28, 2015
Term Loan Collateralized Priority										100.00%	65.00%
Loan pledged as collateral from wholly-owned subsidiary						395,700,000
Minimum amount of debt default for using customary default provisions						50,000,000
Percentage of average interest rate, during period							4.75%
Percentage of average interest rate, end period							4.75%
Unamortized discount balance							1,600,000
Pre-tax interest charge	0	(2,300,000)	0	(8,900,000)									6,600,000
Cash used for payment of term loan													100,000,000
Borrowing from Contran for prepayment of term loan													$ 190,000,000