Long-Term Debt - Long-Term Debt (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Long-term debt
Total debt	$ 960.5	$ 929.0
Less current maturities	9.5	9.3
Total long-term debt	951.0	919.7
VALHI, INC.
Long-term debt
Total debt	513.8	473.7
VALHI, INC. | Contran Credit Facility
Long-term debt
Total debt	263.8	223.7
VALHI, INC. | Notes Payable, Other Payables | Snake River
Long-term debt
Total debt	250.0	250.0
Kronos Worldwide, Inc. | 2014 Term Loan
Long-term debt
Total debt	338.0	340.9
WCS | Financing Capital Lease Obligation
Long-term debt
Total debt	65.6	67.1
Tremont | Promissory Note
Long-term debt
Total debt	17.1	17.4
BMI | Bank note payable
Long-term debt
Total debt	9.3	10.2
LandWell | Unsecured Debt
Long-term debt
Total debt	3.1	3.1
Other Subsidiary | Other
Long-term debt
Total debt	13.6	16.6
Subsidiary
Long-term debt
Total debt	$ 446.7	$ 455.3