Stockholders' Equity - Additional Information (Detail) $ in Millions	3 Months Ended
	Jun. 30, 2022 USD ($) Transaction item shares	Mar. 31, 2022 USD ($) shares	Mar. 31, 2021 USD ($) shares	Sep. 30, 2022 shares
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
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		50,000
Stock repurchase, aggregate purchase price | $	$ 1.7		$ 0.8