Accounts Payable and Accrued Liabilities - Schedule of Accounts Payable and Accrued Liabilities (Detail) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Payable to affiliates:
Accrued litigation settlement	$ 60.0	$ 60.0
Operating lease liability	6.8
Employee benefits	34.8	37.5
Deferred income	18.9	28.3
Accrued sales discounts and rebates	22.1	29.7
Environmental remediation and related costs	6.4	6.5
Interest	1.2	5.2
Other	37.3	33.6
Total	335.7	339.0
Kronos Worldwide, Inc.
Accounts payable:
Accounts payable	111.8	103.2
CompX
Accounts payable:
Accounts payable	3.3	3.2
BMI and LandWell
Accounts payable:
Accounts payable	4.0	2.9
NL
Accounts payable:
Accounts payable	1.2	1.6
Other
Accounts payable:
Accounts payable	0.5	0.6
Contran | Income Taxes Payable
Payable to affiliates:
Payable to affiliates	12.2	10.0
LPC | Trade Accounts Payables
Payable to affiliates:
Payable to affiliates	$ 15.2	$ 16.7