Accounts Payable and Accrued Liabilities - Schedule of Accounts Payable and Accrued Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accounts payable:
Accounts payable	$ 104.8	$ 136.2
Current accrued liabilities:
Employee benefits	24.7	34.6
Accrued sales discounts and rebates	23.9	23.0
Deferred income	21.8	19.8
Environmental remediation and related costs	11.7	10.2	$ 9.1
Accrued workforce reduction costs	5.3
Other	30.4	40.4
Total	121.1	128.0
Noncurrent accrued liabilities:
Reserve for uncertain tax positions	32.9	34.1
Asset retirement obligations	28.8	27.2
Deferred income	20.2	18.9
Employee benefits	7.1	8.1
Insurance claims and expenses	9.6	9.5
Deferred payment obligation	8.8	8.5
Other	7.2	6.4
Total	114.6	112.7
Kronos Worldwide, Inc.
Accounts payable:
Accounts payable	96.1	121.4
CompX
Accounts payable:
Accounts payable	2.7	3.9
WCS
Accounts payable:
Accounts payable	1.3	1.4
BMI/LandWell
Accounts payable:
Accounts payable	2.1	7.0
NL
Accounts payable:
Accounts payable	1.9	2.3
Other
Accounts payable:
Accounts payable	0.7	$ 0.2
Interest Rate Swap Contract
Current accrued liabilities:
Hedging liabilities	$ 3.3