Investment in TiO2 Manufacturing Joint Venture and Other Assets - Summary of Financial Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financial Information [Line Items]
Current assets	$ 1,425.4	$ 1,408.8
Property and equipment, net	563.0	563.5	$ 588.7
Total assets	2,794.4	2,709.6	2,907.5
Other liabilities, primarily current	40.0	33.6
Total liabilities and equity	2,794.4	2,709.6
Net sales	1,938.4	1,889.3	1,904.6
Cost of sales	1,462.9	1,210.9	1,266.5
General and administrative	294.2	310.0	262.6
Total costs and expenses	1,833.7	1,653.1	1,612.8
Net income	78.2	301.0	302.6
LPC
Financial Information [Line Items]
Current assets	94.6	87.0
Property and equipment, net	121.3	119.6
Total assets	215.9	206.6
Other liabilities, primarily current	32.8	41.1
Partners' equity	183.1	165.5
Total liabilities and equity	215.9	206.6
Net sales	353.2	332.9	315.8
Cost of sales	352.8	332.5	315.4
General and administrative	0.4	0.4	0.4
Total costs and expenses	353.2	332.9	315.8
Net income	0.0	0.0	0.0
LPC | Kronos Worldwide, Inc.
Financial Information [Line Items]
Net sales	176.2	165.9	157.5
LPC | Venator Investments LLC
Financial Information [Line Items]
Net sales	$ 177.0	$ 167.0	$ 158.3