Stockholder's Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Class Of Stock [Line Items]
Payments of dividends									$ 11,700	$ 7,800	$ 0
Quarterly dividends paid (in dollars per share)	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.04	$ 0.04	$ 0.04	$ 0.04
NL
Class Of Stock [Line Items]
Common stock awarded to board of directors									13,750	33,250	28,250
Shares available for award	66,150								66,150
NL | Maximum
Class Of Stock [Line Items]
Aggregate of common stock awarded to directors									200,000
CompX
Class Of Stock [Line Items]
Shares available for award	136,450								136,450
CompX | Maximum
Class Of Stock [Line Items]
Aggregate of common stock awarded to directors									200,000
Kronos
Class Of Stock [Line Items]
Shares available for award	120,200								120,200
Kronos | Maximum
Class Of Stock [Line Items]
Aggregate of common stock awarded to directors									200,000