Long-Term Debt - Kronos Senior Secured Notes - Additional Information (Detail) - Kronos Worldwide, Inc. - 3.75% Senior Secured Notes due September 15, 2025 - Kronos International, Inc $ in Millions	6 Months Ended
Jun. 30, 2018 USD ($)	Jun. 30, 2018 EUR (€)
Debt Instrument [Line Items]
Debt instrument interest rate	3.75%	3.75%
Debt instrument maturity date	Sep. 15, 2025
Debt instrument principal amount \| €		€ 400,000,000
Unamortized debt issuance costs \| $	$ 6.8

Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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