Financial Instruments and Fair Value Measurements - Summary of Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Noncontrolling interest in CompX common stock	$ 15,167	$ 14,428
Carrying Amount
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, cash equivalents and restricted cash	93,118	77,975
Noncontrolling interest in CompX common stock	15,167	14,428
Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, cash equivalents and restricted cash	93,118	77,975
Noncontrolling interest in CompX common stock	$ 18,199	$ 19,936