Accounts and Other Receivables, Net - Components of Accounts and Other Receivables (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Trade accounts receivable:
VAT and other receivables	$ 19.9	$ 31.2
Refundable income taxes	2.3	7.9
Allowance for doubtful accounts	(1.7)	(1.2)
Total	333.3	329.2
Trade Accounts Receivable | Kronos Worldwide, Inc.
Trade accounts receivable:
Accounts receivable	295.8	270.5
Trade Accounts Receivable | CompX
Trade accounts receivable:
Accounts receivable	12.3	11.9
Trade Accounts Receivable | BMI and LandWell
Trade accounts receivable:
Accounts receivable	1.8	1.6
Contran | Trade Items
Trade accounts receivable:
Receivable from affiliates	0.4	0.4
LPC
Trade accounts receivable:
Receivable from affiliates		4.7
Other | Trade Items
Trade accounts receivable:
Receivable from affiliates	$ 2.5	$ 2.2