Accounts Payable and Accrued Liabilities - Components of Accounts Payable and Accrued Liabilities (Detail) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Accounts Payable And Accrued Liabilities [Line Items]
Accounts payable	$ 169.2	$ 143.6
Accrued sales discounts and rebates	23.1	28.9
Employee benefits	22.5	28.7
Operating lease liabilities	$ 3.8	$ 3.7
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Total	Total
Other	$ 69.3	$ 52.0
Total	322.6	275.1
LPC
Accounts Payable And Accrued Liabilities [Line Items]
Payables to affiliate	20.8	17.3
Valhi | Income taxes
Accounts Payable And Accrued Liabilities [Line Items]
Payables to affiliate	$ 13.9	$ 0.9