Investment in Kronos Worldwide, Inc. - Selected Financial Information of Kronos Income Statement (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Schedule Of Equity Method Investments [Line Items]
Net sales	$ 40,272	$ 37,971
Cost of sales	28,109	28,304
Income from operations	3,148	1,356
Income tax expense (benefit)	(23)	988
Net income	667	6,839
Kronos | Reportable Legal Entities
Schedule Of Equity Method Investments [Line Items]
Net sales	489,800	478,800
Cost of sales	383,000	407,300
Income from operations	38,400	19,500
Income tax expense (benefit)	7,600	3,500
Net income	$ 18,100	$ 8,100