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 | |||