Equity - Additional Information (Detail) $ in Millions		3 Months Ended
	Apr. 07, 2020	Mar. 31, 2020 USD ($) shares
Kronos Worldwide, Inc.
Equity Class Of Treasury Stock [Line Items]
Common stock, Repurchased		122,489
Stock repurchase, aggregate purchase price | $		$ 1.0
Shares available for purchase		1,600,000
Subsequent Event
Equity Class Of Treasury Stock [Line Items]
Reverse stock split, description	Reverse stock split – As disclosed in our proxy statement filed with the Securities and Exchange Commission on April 7, 2020, our stockholders will vote on a proposal to approve a reverse stock split of our common stock at a reverse stock split ratio of 1-for-8, 1-for-10 or 1-for-12, as determined by our board of directors following stockholder approval, at our annual meeting of stockholders scheduled to be held on May 28, 2020.
Subsequent Event | Scenario One
Equity Class Of Treasury Stock [Line Items]
Reverse stock split, conversion ratio	8
Subsequent Event | Scenario Two
Equity Class Of Treasury Stock [Line Items]
Reverse stock split, conversion ratio	10
Subsequent Event | Scenario Three
Equity Class Of Treasury Stock [Line Items]
Reverse stock split, conversion ratio	12