Goodwill - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2011
Goodwill [Line Items]
Goodwill		$ 27,156,000	$ 27,156,000
Goodwill impairment	6,406,000
Gross goodwill		43,700,000
CompX
Goodwill [Line Items]
Goodwill impairment	10,100,000
Goodwill	14,300,000
EWI Re, Inc.
Goodwill [Line Items]
Goodwill	6,400,000			6,406,000
Goodwill impairment	$ 6,406,000