Summary of Stock Options Activity and Related Information (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Options
Beginning balance	50,000	141,077	1,313,077
Granted	0	0	0
Canceled	0	0	0
Exercised	0	(75,000)	(1,172,000)
Expired/Forfeited	(30,000)	(16,077)	0
Ending balance	20,000	50,000	141,077
Granted	0	0	0
Canceled	0	0	0
Exercisable at December 31, 2016	20,000
Weighted Average Exercise Price
Beginning balance	$ 17.18	$ 11.87	$ 6.22
Granted	0	0	0
Canceled	0	0	0
Exercised	0	9.84	5.49
Expired/Forfeited	20.44	4.82	0
Ending balance	12.29	$ 17.18	$ 11.87
Exercisable at December 31, 2016	$ 12.29