Marketable Securities - Schedule of Marketable Securities (Detail) - USD ($) $ in Thousands |
Dec. 31, 2015 |
Dec. 31, 2014 |
|---|---|---|
| Schedule Of Available For Sale Securities [Line Items] | ||
| Market value | $ 19,260 | $ 92,131 |
| Level 1 | ||
| Schedule Of Available For Sale Securities [Line Items] | ||
| Market value | 19,260 | 92,131 |
| Level 1 | Valhi Inc | Common stock | ||
| Schedule Of Available For Sale Securities [Line Items] | ||
| Market value | 19,260 | 92,131 |
| Cost basis | 24,347 | 24,347 |
| Unrealized gain | $ 67,784 | |
| Unrealized loss | $ (5,087) |