Stockholders' Equity - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Kronos Worldwide, Inc.
Schedule Of Stockholders Equity [Line Items]
Shares acquired	73,881
Shares acquired, value	$ 1.1
Shares available for purchase	1,500,000
Class A \| CompX
Schedule Of Stockholders Equity [Line Items]
Shares acquired		50,000
Shares acquired, value		$ 0.8
Shares available for purchase	600,000

Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

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