Related Party Transactions - Receivables from and Payables to Affiliates (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Current receivables from affiliates:
Receivable from affiliates	$ 13.5	$ 32.6
Current payables to affiliates:
Payable to affiliates	26.7	16.2
Contran
Current receivables from affiliates:
Trade items	0.5	1.0
Income taxes		19.4
Current payables to affiliates:
Contran income taxes	10.0
Noncurrent payable to affiliates:
Contran – income taxes	56.3	70.1
Louisiana Pigment Company
Current receivables from affiliates:
Receivable from affiliates	10.2	8.9
Current payables to affiliates:
Payable to affiliates	16.7	16.2
VALHI, INC. | Contran | Credit Facility
Noncurrent payable to affiliates:
Payables to affiliate included in long-term debt	314.3	284.3
Other
Current receivables from affiliates:
Receivable from affiliates	$ 2.8	$ 3.3