Investment in Kronos Worldwide, Inc. - Selected Financial Information of Kronos Balance Sheet (Detail) (USD $)	Sep. 30, 2012	Dec. 31, 2011
Schedule of Equity Method Investments [Line Items]
Current assets	$ 60,742,000	$ 58,304,000
Property and equipment, net	52,031,000	51,802,000
Investment in TiO2 joint venture	339,393,000	281,257,000
Other noncurrent assets	9,721,000	10,907,000
Total assets	703,653,000	761,242,000
Current liabilities	40,698,000	40,806,000
Long-term debt	21,515,000	27,285,000
Other noncurrent liabilities	18,425,000	19,215,000
Stockholders' equity	379,974,000	414,980,000
Total liabilities and equity	703,653,000	761,242,000
Kronos Worldwide Inc [Member]
Schedule of Equity Method Investments [Line Items]
Current assets	1,054,600,000	865,000,000
Property and equipment, net	491,400,000	485,500,000
Investment in TiO2 joint venture	119,300,000	89,200,000
Other noncurrent assets	370,900,000	384,200,000
Total assets	2,036,200,000	1,823,900,000
Current liabilities	305,500,000	328,000,000
Long-term debt	416,100,000	362,900,000
Accrued pension and postretirement benefits	136,000,000	140,300,000
Other noncurrent liabilities	63,000,000	68,400,000
Stockholders' equity	1,115,600,000	924,300,000
Total liabilities and equity	$ 2,036,200,000	$ 1,823,900,000