Stockholders' Equity - Additional Information (Detail) $ / shares in Units, $ in Millions		6 Months Ended
	May 28, 2020	Jun. 30, 2020 USD ($) $ / shares shares	Jun. 30, 2019 USD ($) shares
Equity Class Of Treasury Stock [Line Items]
Reverse stock split, description	Reverse stock split – On May 28, 2020 following stockholder approval at our annual meeting, our board of directors approved a reverse stock split of our common stock at a ratio of 1-for-12, which was effective on June 1, 2020.
Reverse stock split, conversion ratio	12
Reclassification from common stock to additional paid-in capital | $		$ 3.3
Common stock par value | $ / shares		$ 0.01
Kronos Worldwide, Inc.
Equity Class Of Treasury Stock [Line Items]
Common stock, Repurchased | shares		122,489	110,303
Stock repurchase, aggregate purchase price | $		$ 1.0	$ 1.4
Shares available for purchase | shares		1,600,000