Marketable Securities (Tables)

9 Months Ended

Sep. 30, 2022

Investments Debt And Equity Securities [Abstract]

Classification of Marketable Securities

	Fair value
	measurement	Market		Cost		Unrealized
Marketable security	level	value		basis		gain
		(In millions)
December 31, 2021:
Valhi common stock	1	$	4.1	$	3.2	$	.9
NL and CompX common stocks	1		.1		.1		-
Total		$	4.2	$	3.3	$	.9
September 30, 2022:
Valhi common stock	1	$	3.6	$	3.2	$	.4