Accounts and Other Receivables, Net - Components of Accounts and Other Receivables (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Trade accounts receivable:
VAT and other receivables	$ 22.6	$ 24.3
Refundable income taxes	6.6	8.7
Allowance for doubtful accounts	(1.2)	(1.8)
Total	270.0	303.9
Other
Trade accounts receivable:
Receivable from affiliates	2.6	1.5
Trade Accounts Receivable | Kronos Worldwide, Inc.
Trade accounts receivable:
Accounts receivable	220.0	230.9
Trade Accounts Receivable | CompX
Trade accounts receivable:
Accounts receivable	11.7	8.8
Trade Accounts Receivable | WCS
Trade accounts receivable:
Accounts receivable	5.0	7.7
Trade Accounts Receivable | BMI and LandWell
Trade accounts receivable:
Accounts receivable	0.9	1.4
Trade Items | LPC
Trade accounts receivable:
Receivable from affiliates		13.0
Trade Items | Contran
Trade accounts receivable:
Receivable from affiliates	0.2	0.2
Income Taxes | Contran
Trade accounts receivable:
Receivable from affiliates	$ 1.6	$ 9.2