Summary of Stock Options Activity and Related Information (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Options
Beginning balance	141,077	1,313,077	1,444,150
Granted	0	0	0
Exercised	(75,000)	(1,172,000)	(131,073)
Expired/Forfeited	(16,077)
Ending balance	50,000	141,077	1,313,077
Exercisable at December 31, 2015	50,000
Weighted Average Exercise Price
Beginning balance	$ 11.87	$ 6.22	$ 5.90
Exercised	9.84	5.49	2.70
Expired/Forfeited	4.82
Ending balance	17.18	$ 11.87	$ 6.22
Exercisable at December 31, 2015	$ 17.18