Financial Instruments and Fair Value Measurements - Summary of Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Note receivable from affiliate	$ 10,700
Noncontrolling interest in CompX common stock	16,060	$ 15,301
Carrying amount
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, cash equivalents and restricted cash	105,611	100,981
Note receivable from affiliate	10,700
Noncontrolling interest in CompX common stock	16,060	15,301
Fair value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, cash equivalents and restricted cash	105,611	100,981
Note receivable from affiliate	10,700
Noncontrolling interest in CompX common stock	$ 19,269	$ 18,878