Summary of Stock Options Activity and Related Information (Detail) - $ / shares	3 Months Ended	6 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2014	Jun. 30, 2014	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Options
Beginning balance	1,313,077	1,313,077	1,313,077	1,313,077	1,444,150	1,711,008
Granted	0	0	0	0	0	0
Canceled	0	0	0	0	0	0
Exercised	(40,000)	(137,000)	(162,000)	(1,162,000)	(131,073)	(266,858)
Expired/Forfeited	0	0	0	0	0	0
Ending balance	1,273,077	1,176,077	1,151,077	151,077	1,313,077	1,444,150
Exercisable	1,273,077	1,176,077	1,151,077	151,077
Weighted-Average Exercise Price
Beginning balance	$ 6.22	$ 6.22	$ 6.22	$ 6.22	$ 5.90	$ 5.42
Granted	0	0	0	0	0	0
Canceled	0	0	0	0	0	0
Exercised	3.81	3.04	4.18	5.49	2.70	2.84
Expired/Forfeited	0	0	0	0	0	0
Ending balance	6.30	6.59	6.51	11.87	$ 6.22	$ 5.90
Exercisable	$ 6.30	$ 6.59	$ 6.51	$ 11.87