Marketable securities - Additional Information (Detail) - $ / shares shares in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Minimum
Schedule Of Available For Sale Securities [Line Items]
Maturity term of current marketable securities invested	4 months
Maximum
Schedule Of Available For Sale Securities [Line Items]
Maturity term of current marketable securities invested	12 months
Valhi Inc | Common stock
Schedule Of Available For Sale Securities [Line Items]
Number of shares owned	1.2	1.2
Quoted marked price per share	$ 22.00	$ 28.75