Marketable Securities - Additional Information (Detail) - Valhi Inc - Common stock - USD ($) $ / shares in Units, shares in Millions, $ in Millions |
Feb. 29, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|---|---|---|---|
| Schedule Of Available For Sale Securities [Line Items] | |||
| Outstanding common stock, shares | 14.4 | 14.4 | |
| Common stock quoted market price per share | $ 1.34 | $ 6.41 | |
| Subsequent Event | |||
| Schedule Of Available For Sale Securities [Line Items] | |||
| Difference between aggregate quoted market price and aggregate cost | $ 5.7 |