Marketable securities (Tables)

12 Months Ended

Dec. 31, 2023

Investments, Debt and Equity Securities [Abstract]

Schedule of Marketable Securities

	Fair value			Cost or
	measurement	Market		amortized		Unrealized
	level	value		cost		gain (loss)
		(In thousands)
December 31, 2022
Current assets - fixed income securities	2	$	70,164	$	70,226	$	(62)
Noncurrent assets
Valhi common stock	1	$	26,350	$	24,347	$	2,003
December 31, 2023
Current assets - fixed income securities	2	$	53,149	$	53,181	$	(32)
Noncurrent assets
Valhi common stock	1	$	18,194	$	24,347	$	(6,153)