Investment in Kronos Worldwide, Inc. - Changes in Carrying Value of Investment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Schedule Of Equity Method Investments [Line Items]
Balance at the beginning of the period	$ 250,278
Equity in earnings of Kronos	5,525	$ 2,476
Dividends received from Kronos	(1,761)	$ (6,692)
Equity in Kronos' other comprehensive income (loss):
Balance at the end of the period	259,459
Kronos
Schedule Of Equity Method Investments [Line Items]
Balance at the beginning of the period	250,300
Equity in earnings of Kronos	5,500
Dividends received from Kronos	(1,800)
Equity in Kronos' other comprehensive income (loss):
Currency translation	5,300
Balance at the end of the period	259,500
Kronos | Defined Benefit Pension Plans
Equity in Kronos' other comprehensive income (loss):
Defined benefit pension plans	$ 200