Accounts Payable and Accrued Liabilities - Schedule of Accounts Payable and Accrued Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounts payable:
Accounts payable	$ 94.4	$ 104.8
Current accrued liabilities:
Employee benefits	29.2	24.7
Accrued sales discounts and rebates	22.6	23.9
Deferred income	32.0	21.8
Environmental remediation and related costs	15.3	11.7	$ 10.2
Reserve for uncertain tax positions	3.3
Accrued workforce reduction costs	1.2	5.3
Other	28.8	30.4
Total	135.2	121.1
Noncurrent accrued liabilities:
Reserve for uncertain tax positions	35.7	32.9
Asset retirement obligations	30.7	28.8
Deferred income	12.6	20.2
Employee benefits	7.6	7.1
Insurance claims and expenses	9.5	9.6
Deferred payment obligation	9.0	8.8
Other	8.8	7.2
Total	113.9	114.6
Kronos Worldwide, Inc.
Accounts payable:
Accounts payable	84.9	96.1
CompX
Accounts payable:
Accounts payable	2.6	2.7
WCS
Accounts payable:
Accounts payable	1.6	1.3
BMI/LandWell
Accounts payable:
Accounts payable	2.2	2.1
NL
Accounts payable:
Accounts payable	2.4	1.9
Other
Accounts payable:
Accounts payable	0.7	0.7
Interest Rate Swap Contract
Current accrued liabilities:
Hedging liabilities	$ 2.8	$ 3.3