Fair Value Measurements and Financial Instruments - Additional Information (Detail) - Kronos Worldwide, Inc. - 3.75% Senior Secured Notes due September 15, 2025 - Kronos International, Inc	Mar. 31, 2021 EUR (€)
Financial Instrument At Fair Value [Line Items]
Estimated market price of the notes	€ 1,019
Principal amount of debt instrument	€ 1,000