Goodwill - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Goodwill [Line Items]
Goodwill impairment	$ 0	$ 0	$ 0
Gross goodwill	$ 43,700,000
CompX
Goodwill [Line Items]
Goodwill impairment				$ 10,100,000
EWI Re, Inc.
Goodwill [Line Items]
Goodwill impairment				$ 6,400,000