Investment in Kronos Worldwide, Inc. - Selected Financial Information of Kronos Balance Sheet (Detail) (USD $)	Jun. 30, 2013	Dec. 31, 2012
Schedule of Equity Method Investments [Line Items]
Current assets	$ 107,191,000	$ 112,653,000
Property and equipment, net	34,101,000	34,329,000
Investment in TiO2joint venture	285,099,000	323,128,000
Other noncurrent assets	2,255,000	3,854,000
Total assets	653,287,000	680,782,000
Current liabilities	20,152,000	24,785,000
Long-term debt	16,980,000	17,480,000
Other noncurrent liabilities	18,415,000	18,572,000
Stockholders' equity	355,066,000	374,815,000
Total liabilities and equity	653,287,000	680,782,000
Kronos [Member]
Schedule of Equity Method Investments [Line Items]
Current assets	925,500,000	1,223,400,000
Property and equipment, net	507,900,000	522,500,000
Investment in TiO2joint venture	95,200,000	109,900,000
Other noncurrent assets	213,700,000	171,200,000
Total assets	1,742,300,000	2,027,000,000
Current liabilities	275,700,000	328,400,000
Long-term debt	286,900,000	378,900,000
Accrued pension and postretirement benefits	194,100,000	203,300,000
Other noncurrent liabilities	48,700,000	54,300,000
Stockholders' equity	936,900,000	1,062,100,000
Total liabilities and equity	$ 1,742,300,000	$ 2,027,000,000