Financial Instruments - Summary of Financial Instruments Not Carried at Fair Value (Detail) - USD ($) $ in Thousands |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items] | ||
| Noncontrolling interest in subsidiary | $ 16,350 | $ 15,301 |
| Carrying Amount | ||
| Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items] | ||
| Cash, cash equivalents and restricted cash | 98,242 | 100,981 |
| Carrying Amount | CompX | ||
| Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items] | ||
| Noncontrolling interest in subsidiary | 16,350 | 15,301 |
| Fair Value | ||
| Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items] | ||
| Cash, cash equivalents and restricted cash | 98,242 | 100,981 |
| Fair Value | CompX | ||
| Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items] | ||
| Noncontrolling interest in subsidiary | $ 26,790 | $ 18,878 |