Accounts and Other Receivables, Net - Components of Accounts and Other Receivables (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Trade accounts receivable:
VAT and other receivables	$ 28.7	$ 32.7
Allowance for doubtful accounts	(1.3)	(1.3)
Total	357.0	303.3
Trade Accounts Receivable | Kronos Worldwide, Inc.
Trade accounts receivable:
Accounts receivable	288.4	226.1
Trade Accounts Receivable | CompX
Trade accounts receivable:
Accounts receivable	11.8	8.7
Trade Accounts Receivable | WCS
Trade accounts receivable:
Accounts receivable	11.7	7.2
Trade Accounts Receivable | BMI and LandWell
Trade accounts receivable:
Accounts receivable	1.5
Tax Refund Receivable
Trade accounts receivable:
Refundable income taxes	10.5	15.2
Contran | Receivable From Affiliates
Trade accounts receivable:
Receivable from affiliates	4.2
LPC | Receivable From Affiliates
Trade accounts receivable:
Receivable from affiliates: LPC - trade items		14.2
Other | Receivable From Affiliates
Trade accounts receivable:
Receivable from affiliates	$ 1.5	$ 0.5