Accounts Payable and Accrued Liabilities - Schedule of Accounts Payable and Accrued Liabilities (Detail) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Payable to affiliates:
Employee benefits	$ 22.6	$ 24.7
Deferred income	17.5	21.8
Accrued sales discounts and rebates	23.9	23.9
Environmental remediation and related costs	14.4	11.7
Accrued workforce reduction costs	4.8	5.3
Other	29.5	30.4
Total	259.8	271.4
Kronos Worldwide, Inc.
Accounts payable:
Accounts payable	93.5	96.1
CompX
Accounts payable:
Accounts payable	3.0	2.7
WCS
Accounts payable:
Accounts payable	0.8	1.3
BMI and LandWell
Accounts payable:
Accounts payable	1.6	2.1
Other
Accounts payable:
Accounts payable	2.9	2.6
Contran | Trade Accounts Payables
Payable to affiliates:
Payable to affiliates	27.4	26.1
LPC | Trade Accounts Payables
Payable to affiliates:
Payable to affiliates	14.5	19.4
Interest Rate Swap
Payable to affiliates:
Hedging liabilities	$ 3.4	$ 3.3