Marketable Securities (Tables)

3 Months Ended

Mar. 31, 2017

Investments Debt And Equity Securities [Abstract]

Schedule of Marketable Securities

	Fair value measurement level	Market value		Cost basis		Unrealized gain (loss)
		(In thousands)
December 31, 2016
Valhi common stock	1	$	49,731	$	24,347	$	25,384
March 31, 2017
Valhi common stock	1	$	47,143	$	24,347	$	22,796