Warrants - Summary of Warrant Activity (Detail) - Warrants Not Settleable in Cash [Member] - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Class of Warrant or Right [Line Items]
Beginning balance	1,426,622	1,313,719	1,285,394
Number of Warrants, Granted		112,903	38,325
Number of Warrants, Exercised			(10,000)
Ending balance	1,426,622	1,426,622	1,313,719	1,285,394
Weighted Average Exercise Price, Outstanding	$ 1.81	$ 1.70	$ 1.45
Weighted Average Exercise Price, Granted		3.10	4.02
Weighted Average Exercise Price, Exercised			1.65
Weighted Average Exercise Price, Outstanding	$ 1.81	$ 1.81	$ 1.70	$ 1.45
Weighted Average Remaining Contractual Life, Outstanding	2 years 2 months 12 days	3 years 2 months 12 days	3 years 10 months 24 days	4 years 8 months 12 days
Weighted Average Remaining Contractual Life, Granted		6 years 7 months 6 days	6 years 8 months 12 days
Weighted Average Fair Value, Outstanding	$ 1.54	$ 1.75	$ 1.75
Weighted Average Fair Value, Granted		0.86	1.41
Weighted Average Fair Value, Outstanding	$ 1.54	$ 1.54	$ 1.75	$ 1.75