Summary of Status of Company's Stock Option Plan (Detail) (Stock Option Plan, USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Stock Option Plan
Shares
Outstanding at beginning of period	3,280,874	2,517,911
Exercised	(50,500)	(292,537)
Granted	70,000	1,055,500
Outstanding at end of period	3,300,374	3,280,874
Weighted Average Exercise Price
Outstanding at beginning of period	$ 1.98	$ 1.33
Exercised	$ 1.39	$ 1.03
Granted	$ 3.60	$ 3.28
Outstanding at end of period	$ 2.02	$ 1.98