Investment in Kronos Worldwide, Inc. - Changes in Carrying Value of Investment (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Schedule Of Equity Method Investments [Line Items]
Balance at the beginning of the period			$ 247,582
Equity in earnings of Kronos	$ 5,973	$ (2,516)	8,449	$ (7,153)
Dividends received from Kronos			(13,384)	$ (13,384)
Equity in Kronos' other comprehensive income (loss):
Balance at the end of the period	237,268		237,268
Kronos
Schedule Of Equity Method Investments [Line Items]
Balance at the beginning of the period			247,600
Equity in earnings of Kronos			8,400
Dividends received from Kronos			(13,400)
Equity in Kronos' other comprehensive income (loss):
Currency translation			(5,600)
Balance at the end of the period	$ 237,300		237,300
Kronos | Defined Benefit Pension Plans
Equity in Kronos' other comprehensive income (loss):
Defined benefit pension plans			$ 300