Stock Options, Stock Purchase Plan and Warrants - Summary of Warrant Activity (Detail) - Warrant [Member] - $ / shares					12 Months Ended
	Mar. 16, 2014	Mar. 12, 2014	Feb. 07, 2014	Jan. 09, 2012	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Warrants outstanding, beginning balance					650,000	1,358,333	1,358,333
Warrants, Granted				200,000	0	0	0
Warrants, Exercised		(375,000)	(83,333)		0	(458,333)	0
Warrants, Expired	(250,000)				0	(250,000)	0
Warrants, Cancelled					0	0	0
Warrants outstanding, ending balance					650,000	650,000	1,358,333
Warrants exercisable, ending balance					530,000
Weighted Average Exercise Price Warrants outstanding, beginning balance					$ 1.48	$ 1.24	$ 1.24
Weighted average exercise price, granted				$ 1.43	0	0	0
Weighted Average Exercised Price, Exercised					0	0	0
Weighted Average Exercised Price, Expired					$ 0	$ 0	$ 0
Weighted Average Exercised Price, Cancelled					0	0	0
Weighted Average Exercised Price, Warrants outstanding, ending balance					$ 1.48	$ 1.48	$ 1.24
Weighted Average Exercised Price, Warrants exercisable, ending balance					$ 1.49