Stockholders' Equity - Additional Information (Detail) $ in Millions	3 Months Ended	9 Months Ended
	Jun. 30, 2022 USD ($) item Transaction shares	Sep. 30, 2023 USD ($) shares	Sep. 30, 2022 USD ($) shares
Kronos Worldwide, Inc.
Schedule Of Stockholders Equity [Line Items]
Shares acquired		313,814	73,881
Shares acquired, value | $		$ 2.8	$ 1.1
Shares available for purchase		1,000,000.0
CompX
Schedule Of Stockholders Equity [Line Items]
Shares available for purchase		500,000
NL
Schedule Of Stockholders Equity [Line Items]
Common stock, Repurchased	2,000
Shares Repurchased in Market Transaction | CompX
Schedule Of Stockholders Equity [Line Items]
Common stock, Repurchased	70,000
Shares Repurchased from Affiliates
Schedule Of Stockholders Equity [Line Items]
Number of affiliates | item	2
Number of private transactions | Transaction	2
Shares Repurchased from Affiliates | CompX
Schedule Of Stockholders Equity [Line Items]
Common stock, Repurchased	8,900
Class A | CompX
Schedule Of Stockholders Equity [Line Items]
Common stock, Repurchased	78,900
Stock repurchase, aggregate purchase price | $	$ 1.7