Investment in Kronos Worldwide, Inc. - Selected Financial Information of Kronos Balance Sheet (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Schedule Of Equity Method Investments [Line Items]
Current assets	$ 171,644	$ 164,684
Other noncurrent assets	5,386	5,860
Total assets	546,466	557,492
Current liabilities	26,347	29,808
Stockholders' equity	303,267	304,506
Total liabilities and equity	546,466	557,492
Kronos
Schedule Of Equity Method Investments [Line Items]
Current assets	1,171,000	1,219,700
Property and equipment, net	467,700	490,600
Investment in TiO2 joint venture	96,500	90,200
Other noncurrent assets	168,500	165,300
Total assets	1,903,700	1,965,800
Current liabilities	230,000	270,600
Long-term debt	445,000	444,000
Accrued pension costs	307,700	307,400
Other noncurrent liabilities	119,700	127,700
Stockholders' equity	801,300	816,100
Total liabilities and equity	$ 1,903,700	$ 1,965,800