Investment in Kronos Worldwide, Inc. - Selected Financial Information of Kronos Balance Sheet (Detail) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Schedule Of Equity Method Investments [Line Items]
Current assets	$ 179,619	$ 237,958
Property and equipment, net	23,552	24,026
Other noncurrent assets	983	1,034
Total assets	520,025	578,258
Current liabilities	30,937	91,062
Accrued pension costs	78	76
Other noncurrent liabilities	1,363	6,183
Stockholders' equity	397,644	396,904
Total liabilities and equity	520,025	578,258
Kronos | Reportable Legal Entities
Schedule Of Equity Method Investments [Line Items]
Current assets	1,126,000	1,105,300
Property and equipment, net	705,400	694,100
Other noncurrent assets	114,600	114,100
Total assets	1,946,000	1,913,500
Current liabilities	430,300	476,600
Long-term debt	476,000	429,100
Accrued pension costs	119,300	117,500
Other noncurrent liabilities	73,400	73,300
Stockholders' equity	847,000	817,000
Total liabilities and equity	$ 1,946,000	$ 1,913,500