Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Tax Disclosure [Line Items]
Dividends received from Kronos Worldwide, Inc.	$ 6,339	$ 5,987
Kronos
Income Tax Disclosure [Line Items]
Dividends received from Kronos Worldwide, Inc.	$ 6,300	$ 6,000
Kronos German Subsidiary | Germany- Canada APA | Germany Revenue Agency | Earliest Tax Year
Income Tax Disclosure [Line Items]
Effective tax year		2005
Kronos German Subsidiary | Germany- Canada APA | Germany Revenue Agency | Latest Tax Year
Income Tax Disclosure [Line Items]
Effective tax year		2017
Kronos Canadian And German Subsidiaries | Germany- Canada APA
Income Tax Disclosure [Line Items]
Non-cash income tax benefit		$ 1,400